[DOC] Fixed Mesos version in doc from 0.18.1 to 0.21.0
[DOC] Fixed Mesos version in doc from 0.18.1 to 0.21.0

#3934 upgraded Mesos version so we should also fix docs right?

This issue is really minor so I don't file in JIRA.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #3982 from sarutak/fix-mesos-version and squashes the following commits:

9a86ee3 [Kousuke Saruta] Fixed mesos version from 0.18.1 to 0.21.0

esi-mineset/spark,kimoonkim/spark,jkbradley/spark,mdespriee/spark,vinodkc/spark,nilsgrabbert/spark,aokolnychyi/spark,zero323/spark,SHASHANKB/spark,wangyum/spark,taroplus/spark,UndeadBaneGitHub/spark,hhbyyh/spark,mike0sv/spark,ConeyLiu/spark,ddna1021/spark,ericvandenbergfb/spark,taroplus/spark,bOOm-X/spark,andrewor14/iolap,gioenn/xSpark,facaiy/spark,adrian-ionescu/apache-spark,tejasapatil/spark,actuaryzhang/spark,shaneknapp/spark,milliman/spark,spark-test/spark,actuaryzhang/spark,joseph-torres/spark,hhbyyh/spark,cin/spark,apache/spark,sachintyagi22/spark,liyichao/spark,tejasapatil/spark,andrewor14/spark,zero323/spark,jianran/spark,WeichenXu123/spark,WeichenXu123/spark,Panos-Bletsos/spark-cost-model-optimizer,SHASHANKB/spark,rekhajoshm/spark,goldmedal/spark,shaneknapp/spark,jrshust/spark,dbtsai/spark,ioana-delaney/spark,techaddict/spark,huang1900/spark,WindCanDie/spark,kiszk/spark,wangmiao1981/spark,cin/spark,liyichao/spark,dbtsai/spark,markhamstra/spark,WindCanDie/spark,pgandhi999/spark,zhouyejoe/spark,hvanhovell/spark,shuangshuangwang/spark,UndeadBaneGitHub/spark,rednaxelafx/apache-spark,cin/spark,rekhajoshm/spark,hhbyyh/spark,jlopezmalla/spark,spark-test/spark,kissmetrics/spark,highfei2011/spark,setjet/spark,1haodian/spark,apache-spark-on-k8s/spark,dongjoon-hyun/spark,goldmedal/spark,narahari92/spark,facaiy/spark,hhbyyh/spark,cin/spark,taroplus/spark,mzl9039/spark,cin/spark,dongjoon-hyun/spark,goldmedal/spark,1haodian/spark,ueshin/apache-spark,hhbyyh/spark,jiangxb1987/spark,aray/spark,jianran/spark,mahak/spark,gengliangwang/spark,lvdongr/spark,ptkool/spark,poffuomo/spark,jianran/spark,techaddict/spark,poffuomo/spark,someorz/spark,jrshust/spark,xuanyuanking/spark,bOOm-X/spark,bravo-zhang/spark,facaiy/spark,ahnqirage/spark,skonto/spark,nchammas/spark,rekhajoshm/spark,LantaoJin/spark,loneknightpy/spark,witgo/spark,UndeadBaneGitHub/spark,SnappyDataInc/spark,shaneknapp/spark,spark-test/spark,sachintyagi22/spark,HyukjinKwon/spark,tengpeng/spark,HyukjinKwon/spark,szhem/spark,saltstar/spark,lxsmnv/spark,mzl9039/spark,SnappyDataInc/spark,nchammas/spark,adrian-ionescu/apache-spark,ddna1021/spark,ahnqirage/spark,rezasafi/spark,xflin/spark,highfei2011/spark,aray/spark,srowen/spark,wzhfy/spark,skonto/spark,stanzhai/spark,akopich/spark,shuangshuangwang/spark,guoxiaolongzte/spark,darionyaphet/spark,mike0sv/spark,rednaxelafx/apache-spark,esi-mineset/spark,ConeyLiu/spark,joseph-torres/spark,rikima/spark,JoshRosen/spark,hvanhovell/spark,sahilTakiar/spark,gioenn/xSpark,kimoonkim/spark,ajaysaini725/spark,huang1900/spark,liutang123/spark,publicRoman/spark,holdenk/spark,sachintyagi22/spark,big-pegasus/spark,caneGuy/spark,szhem/spark,brad-kaiser/spark,sahilTakiar/spark,sureshthalamati/spark,dhruve/spark,janewangfb/spark,zzcclp/spark,map222/spark,tengpeng/spark,darionyaphet/spark,shaneknapp/spark,vinodkc/spark,big-pegasus/spark,kimoonkim/spark,pronix/spark,mzl9039/spark,bdrillard/spark,tejasapatil/spark,andrewor14/spark,dbtsai/spark,witgo/spark,haowu80s/spark,nlalevee/spark,aosagie/spark,BryanCutler/spark,jiangxb1987/spark,saturday-shi/spark,minixalpha/spark,liutang123/spark,JerryLead/spark,JerryLead/spark,jlopezmalla/spark,shubhamchopra/spark,highfei2011/spark,szhem/spark,map222/spark,hvanhovell/spark,mahak/spark,JerryLead/spark,zuotingbing/spark,akopich/spark,liyichao/spark,lvdongr/spark,jiangxb1987/spark,nilsgrabbert/spark,michalsenkyr/spark,ahnqirage/spark,patrick-nicholson/spark,lvdongr/spark,lxsmnv/spark,highfei2011/spark,hhbyyh/spark,zzcclp/spark,metamx/spark,michalsenkyr/spark,caneGuy/spark,mzl9039/spark,pgandhi999/spark,mahak/spark,dbtsai/spark,dbtsai/spark,vinodkc/spark,rezasafi/spark,jrshust/spark,ericvandenbergfb/spark,UndeadBaneGitHub/spark,joseph-torres/spark,aray/spark,zzcclp/spark,gioenn/xSpark,ueshin/apache-spark,JerryLead/spark,saturday-shi/spark,map222/spark,publicRoman/spark,mahak/spark,patrick-nicholson/spark,nlalevee/spark,skonto/spark,jkbradley/spark,huang1900/spark,mdespriee/spark,saturday-shi/spark,kiszk/spark,darionyaphet/spark,nlalevee/spark,ahnqirage/spark,kissmetrics/spark,metamx/spark,jkbradley/spark,jiangxb1987/spark,liutang123/spark,loneknightpy/spark,Panos-Bletsos/spark-cost-model-optimizer,jlopezmalla/spark,taroplus/spark,wangmiao1981/spark,JoshRosen/spark,rednaxelafx/apache-spark,UndeadBaneGitHub/spark,yanboliang/spark,LantaoJin/spark,jkbradley/spark,hvanhovell/spark,rekhajoshm/spark,nilsgrabbert/spark,esi-mineset/spark,huang1900/spark,akopich/spark,mahak/spark,matthewfranglen/spark,janewangfb/spark,byakuinss/spark,shuangshuangwang/spark,nchammas/spark,panfengfeng/spark,HyukjinKwon/spark,ConeyLiu/spark,rikima/spark,WindCanDie/spark,dhruve/spark,Panos-Bletsos/spark-cost-model-optimizer,andrewor14/spark,kiszk/spark,facaiy/spark,narahari92/spark,dhruve/spark,ahnqirage/spark,JoshRosen/spark,byakuinss/spark,holdenk/spark,loneknightpy/spark,gioenn/xSpark,stanzhai/spark,goldmedal/spark,dongjoon-hyun/spark,sachintyagi22/spark,liyichao/spark,someorz/spark,witgo/spark,icexelloss/spark,gengliangwang/spark,srowen/spark,actuaryzhang/spark,MLnick/spark,ron8hu/spark,maropu/spark,rikima/spark,szhem/spark,witgo/spark,xuanyuanking/spark,guoxiaolongzte/spark,janewangfb/spark,pronix/spark,icexelloss/spark,jkbradley/spark,LantaoJin/spark,ajaysaini725/spark,michalsenkyr/spark,maropu/spark,rikima/spark,kevinyu98/spark,ptkool/spark,zuotingbing/spark,michalsenkyr/spark,cloud-fan/spark,zhouyejoe/spark,skonto/spark,bOOm-X/spark,ibm-research-ireland/sparkoscope,alunarbeach/spark,aosagie/spark,HyukjinKwon/spark,map222/spark,andrewor14/iolap,MLnick/spark,map222/spark,brad-kaiser/spark,milliman/spark,liyichao/spark,saltstar/spark,hhbyyh/spark,eyalfa/spark,spark-test/spark,milliman/spark,patrick-nicholson/spark,aokolnychyi/spark,xuanyuanking/spark,mike0sv/spark,WindCanDie/spark,dhruve/spark,joseph-torres/spark,minixalpha/spark,panfengfeng/spark,gengliangwang/spark,nilsgrabbert/spark,BryanCutler/spark,sachintyagi22/spark,mdespriee/spark,kissmetrics/spark,HyukjinKwon/spark,haowu80s/spark,poffuomo/spark,andrewor14/iolap,metamx/spark,ueshin/apache-spark,ueshin/apache-spark,debugger87/spark,ptkool/spark,kiszk/spark,nilsgrabbert/spark,caneGuy/spark,mahak/spark,zuotingbing/spark,tejasapatil/spark,huang1900/spark,sachintyagi22/spark,highfei2011/spark,rednaxelafx/apache-spark,someorz/spark,liutang123/spark,debugger87/spark,MLnick/spark,saltstar/spark,nilsgrabbert/spark,gioenn/xSpark,panfengfeng/spark,SHASHANKB/spark,narahari92/spark,kiszk/spark,patrick-nicholson/spark,ajaysaini725/spark,dongjoon-hyun/spark,caneGuy/spark,zuotingbing/spark,1haodian/spark,cloud-fan/spark,ueshin/apache-spark,goldmedal/spark,cloud-fan/spark,bdrillard/spark,WindCanDie/spark,michalsenkyr/spark,minixalpha/spark,aokolnychyi/spark,UndeadBaneGitHub/spark,hvanhovell/spark,adrian-ionescu/apache-spark,esi-mineset/spark,actuaryzhang/spark,ericvandenbergfb/spark,shubhamchopra/spark,ericvandenbergfb/spark,publicRoman/spark,jianran/spark,markhamstra/spark,1haodian/spark,kiszk/spark,nilsgrabbert/spark,guoxiaolongzte/spark,debugger87/spark,alunarbeach/spark,ericvandenbergfb/spark,lvdongr/spark,debugger87/spark,metamx/spark,ptkool/spark,aray/spark,SHASHANKB/spark,nlalevee/spark,poffuomo/spark,ibm-research-ireland/sparkoscope,milliman/spark,JoshRosen/spark,stanzhai/spark,wangmiao1981/spark,cin/spark,zhouyejoe/spark,kevinyu98/spark,publicRoman/spark,kissmetrics/spark,adrian-ionescu/apache-spark,xuanyuanking/spark,1haodian/spark,nchammas/spark,vinodkc/spark,nlalevee/spark,saltstar/spark,zhouyejoe/spark,srowen/spark,bOOm-X/spark,holdenk/spark,kevinyu98/spark,setjet/spark,facaiy/spark,gengliangwang/spark,hvanhovell/spark,markhamstra/spark,sahilTakiar/spark,actuaryzhang/spark,zero323/spark,bdrillard/spark,BryanCutler/spark,rezasafi/spark,UndeadBaneGitHub/spark,someorz/spark,jiangxb1987/spark,wangyum/spark,mike0sv/spark,rednaxelafx/apache-spark,bravo-zhang/spark,huang1900/spark,ioana-delaney/spark,liutang123/spark,akopich/spark,Aegeaner/spark,loneknightpy/spark,brad-kaiser/spark,byakuinss/spark,HyukjinKwon/spark,cloud-fan/spark,loneknightpy/spark,ibm-research-ireland/sparkoscope,saturday-shi/spark,bdrillard/spark,srowen/spark,kevinyu98/spark,someorz/spark,szhem/spark,setjet/spark,kevinyu98/spark,1haodian/spark,mahak/spark,andrewor14/spark,janewangfb/spark,ddna1021/spark,tengpeng/spark,alunarbeach/spark,spark-test/spark,LantaoJin/spark,esi-mineset/spark,map222/spark,akopich/spark,sureshthalamati/spark,shubhamchopra/spark,wangyum/spark,xuanyuanking/spark,wzhfy/spark,holdenk/spark,poffuomo/spark,Aegeaner/spark,zzcclp/spark,bOOm-X/spark,adrian-ionescu/apache-spark,chuckchen/spark,zuotingbing/spark,MLnick/spark,rekhajoshm/spark,skonto/spark,dhruve/spark,joseph-torres/spark,Aegeaner/spark,ron8hu/spark,aray/spark,joseph-torres/spark,michalsenkyr/spark,big-pegasus/spark,map222/spark,joseph-torres/spark,Panos-Bletsos/spark-cost-model-optimizer,publicRoman/spark,pronix/spark,Aegeaner/spark,brad-kaiser/spark,xflin/spark,adrian-ionescu/apache-spark,MLnick/spark,vinodkc/spark,byakuinss/spark,panfengfeng/spark,apache/spark,maropu/spark,ioana-delaney/spark,big-pegasus/spark,wangmiao1981/spark,mzl9039/spark,mdespriee/spark,setjet/spark,poffuomo/spark,milliman/spark,nchammas/spark,aokolnychyi/spark,ahnqirage/spark,eyalfa/spark,andrewor14/iolap,aray/spark,aokolnychyi/spark,bdrillard/spark,pgandhi999/spark,ajaysaini725/spark,jkbradley/spark,mzl9039/spark,lxsmnv/spark,debugger87/spark,taroplus/spark,narahari92/spark,saltstar/spark,shubhamchopra/spark,ron8hu/spark,andrewor14/iolap,jiangxb1987/spark,Aegeaner/spark,kissmetrics/spark,caneGuy/spark,dongjoon-hyun/spark,sahilTakiar/spark,pgandhi999/spark,publicRoman/spark,shubhamchopra/spark,ron8hu/spark,bdrillard/spark,apache/spark,mdespriee/spark,brad-kaiser/spark,apache-spark-on-k8s/spark,apache/spark,kimoonkim/spark,aosagie/spark,alunarbeach/spark,byakuinss/spark,wangmiao1981/spark,skonto/spark,sahilTakiar/spark,kimoonkim/spark,bdrillard/spark,BryanCutler/spark,jlopezmalla/spark,holdenk/spark,zero323/spark,maropu/spark,jkbradley/spark,loneknightpy/spark,shuangshuangwang/spark,ddna1021/spark,sureshthalamati/spark,sureshthalamati/spark,aosagie/spark,liyichao/spark,esi-mineset/spark,highfei2011/spark,alunarbeach/spark,mdespriee/spark,zuotingbing/spark,maropu/spark,srowen/spark,xuanyuanking/spark,SnappyDataInc/spark,jrshust/spark,aosagie/spark,spark-test/spark,ajaysaini725/spark,facaiy/spark,haowu80s/spark,someorz/spark,xflin/spark,jianran/spark,tengpeng/spark,loneknightpy/spark,rekhajoshm/spark,MLnick/spark,akopich/spark,metamx/spark,yanboliang/spark,ericvandenbergfb/spark,rekhajoshm/spark,chuckchen/spark,panfengfeng/spark,chuckchen/spark,icexelloss/spark,actuaryzhang/spark,mike0sv/spark,cloud-fan/spark,markhamstra/spark,sureshthalamati/spark,rezasafi/spark,pgandhi999/spark,techaddict/spark,szhem/spark,pgandhi999/spark,apache/spark,xflin/spark,zhouyejoe/spark,janewangfb/spark,wzhfy/spark,guoxiaolongzte/spark,WeichenXu123/spark,apache-spark-on-k8s/spark,JoshRosen/spark,icexelloss/spark,bOOm-X/spark,wangyum/spark,ddna1021/spark,michalsenkyr/spark,jlopezmalla/spark,bravo-zhang/spark,actuaryzhang/spark,witgo/spark,nlalevee/spark,ron8hu/spark,metamx/spark,apache-spark-on-k8s/spark,metamx/spark,sahilTakiar/spark,wzhfy/spark,techaddict/spark,setjet/spark,HyukjinKwon/spark,ron8hu/spark,patrick-nicholson/spark,alunarbeach/spark,xflin/spark,someorz/spark,vinodkc/spark,stanzhai/spark,sureshthalamati/spark,ioana-delaney/spark,minixalpha/spark,kimoonkim/spark,saltstar/spark,nchammas/spark,LantaoJin/spark,ibm-research-ireland/sparkoscope,narahari92/spark,WeichenXu123/spark,rezasafi/spark,mike0sv/spark,ron8hu/spark,guoxiaolongzte/spark,rednaxelafx/apache-spark,lxsmnv/spark,andrewor14/spark,ueshin/apache-spark,WindCanDie/spark,zero323/spark,lvdongr/spark,ioana-delaney/spark,jrshust/spark,techaddict/spark,stanzhai/spark,mike0sv/spark,Aegeaner/spark,wangyum/spark,icexelloss/spark,kiszk/spark,ajaysaini725/spark,yanboliang/spark,sureshthalamati/spark,facaiy/spark,zzcclp/spark,yanboliang/spark,chuckchen/spark,lxsmnv/spark,jiangxb1987/spark,pronix/spark,rezasafi/spark,spark-test/spark,pronix/spark,Aegeaner/spark,markhamstra/spark,andrewor14/spark,rikima/spark,goldmedal/spark,brad-kaiser/spark,SnappyDataInc/spark,ioana-delaney/spark,gengliangwang/spark,pronix/spark,setjet/spark,ptkool/spark,ddna1021/spark,BryanCutler/spark,zhouyejoe/spark,kimoonkim/spark,apache-spark-on-k8s/spark,big-pegasus/spark,jlopezmalla/spark,Panos-Bletsos/spark-cost-model-optimizer,ConeyLiu/spark,apache-spark-on-k8s/spark,ddna1021/spark,apache/spark,icexelloss/spark,milliman/spark,liyichao/spark,taroplus/spark,xuanyuanking/spark,witgo/spark,wangmiao1981/spark,saturday-shi/spark,JoshRosen/spark,ConeyLiu/spark,haowu80s/spark,janewangfb/spark,wangmiao1981/spark,goldmedal/spark,brad-kaiser/spark,dongjoon-hyun/spark,MLnick/spark,big-pegasus/spark,xflin/spark,rezasafi/spark,minixalpha/spark,BryanCutler/spark,stanzhai/spark,JerryLead/spark,shaneknapp/spark,wzhfy/spark,jlopezmalla/spark,Panos-Bletsos/spark-cost-model-optimizer,liutang123/spark,eyalfa/spark,rikima/spark,darionyaphet/spark,mdespriee/spark,esi-mineset/spark,ibm-research-ireland/sparkoscope,darionyaphet/spark,minixalpha/spark,wangyum/spark,tejasapatil/spark,WeichenXu123/spark,gioenn/xSpark,ibm-research-ireland/sparkoscope,yanboliang/spark,shuangshuangwang/spark,witgo/spark,JerryLead/spark,SHASHANKB/spark,big-pegasus/spark,lvdongr/spark,shubhamchopra/spark,lxsmnv/spark,SnappyDataInc/spark,tengpeng/spark,WeichenXu123/spark,skonto/spark,saturday-shi/spark,lxsmnv/spark,SnappyDataInc/spark,ConeyLiu/spark,mzl9039/spark,jrshust/spark,icexelloss/spark,vinodkc/spark,liutang123/spark,andrewor14/iolap,kevinyu98/spark,andrewor14/iolap,narahari92/spark,JoshRosen/spark,zuotingbing/spark,aokolnychyi/spark,yanboliang/spark,kevinyu98/spark,dhruve/spark,ueshin/apache-spark,lvdongr/spark,yanboliang/spark,SHASHANKB/spark,zzcclp/spark,ajaysaini725/spark,saltstar/spark,srowen/spark,zhouyejoe/spark,chuckchen/spark,debugger87/spark,dongjoon-hyun/spark,pgandhi999/spark,shaneknapp/spark,wzhfy/spark,publicRoman/spark,dhruve/spark,darionyaphet/spark,ConeyLiu/spark,aosagie/spark,taroplus/spark,cin/spark,patrick-nicholson/spark,tengpeng/spark,dbtsai/spark,huang1900/spark,panfengfeng/spark,zzcclp/spark,poffuomo/spark,markhamstra/spark,alunarbeach/spark,bOOm-X/spark,LantaoJin/spark,chuckchen/spark,tengpeng/spark,nlalevee/spark,setjet/spark,WindCanDie/spark,szhem/spark,WeichenXu123/spark,caneGuy/spark,panfengfeng/spark,gioenn/xSpark,cloud-fan/spark,bravo-zhang/spark,zero323/spark,guoxiaolongzte/spark,xflin/spark,1haodian/spark,kissmetrics/spark,ahnqirage/spark,haowu80s/spark,janewangfb/spark,nchammas/spark,BryanCutler/spark,byakuinss/spark,maropu/spark,highfei2011/spark,ioana-delaney/spark,SHASHANKB/spark,eyalfa/spark,rikima/spark,jrshust/spark,ptkool/spark,apache-spark-on-k8s/spark,tejasapatil/spark,dbtsai/spark,hvanhovell/spark,srowen/spark,wangyum/spark,tejasapatil/spark,ibm-research-ireland/sparkoscope,shuangshuangwang/spark,caneGuy/spark,patrick-nicholson/spark,darionyaphet/spark,zero323/spark,markhamstra/spark,aray/spark,gengliangwang/spark,jianran/spark,Panos-Bletsos/spark-cost-model-optimizer,kissmetrics/spark,bravo-zhang/spark,debugger87/spark,adrian-ionescu/apache-spark,LantaoJin/spark,ericvandenbergfb/spark,techaddict/spark,shaneknapp/spark,gengliangwang/spark,andrewor14/spark,jianran/spark,sachintyagi22/spark,bravo-zhang/spark,chuckchen/spark,byakuinss/spark,maropu/spark,holdenk/spark,minixalpha/spark,milliman/spark,stanzhai/spark,guoxiaolongzte/spark,haowu80s/spark,shuangshuangwang/spark,rednaxelafx/apache-spark,sahilTakiar/spark,eyalfa/spark,eyalfa/spark,eyalfa/spark,techaddict/spark,bravo-zhang/spark,aosagie/spark,holdenk/spark,saturday-shi/spark,ptkool/spark,SnappyDataInc/spark,wzhfy/spark,apache/spark,akopich/spark,cloud-fan/spark,narahari92/spark,JerryLead/spark,aokolnychyi/spark,shubhamchopra/spark