updated readme.md with 2.1
updated readme.md with 2.1

greyheart/spark,sebastian1118/spark,seetharamireddy540/spark,stylismo/spark,marstianna/spark,guilhermehbueno/spark,martylamb/spark,marstianna/spark,northcapen/spark,despegar/spark,gimlet2/spark,rokusr/spark,micsta/spark,opsonsy/spark,jabgibson/spark,guicamest/spark,heuermh/spark-1,mugizico/spark,ztx1491/spark,gimlet2/spark,micsta/spark,borud/spark,jabgibson/spark,nkhuyu/spark-1,nacx/spark,northcapen/spark,universsky/spark-1,perwendel/spark,Ariel-Isaacm/spark,guicamest/spark,seetharamireddy540/spark,heuermh/spark-1,gutobortolozzo/spark,jacek99/spark,sebastian1118/spark,tempbottle/spark-1,alexlondon07/spark,micsta/spark,arekkw/spark,stylismo/spark,xdcrafts/spark,rokusr/spark,hendrosteven/spark,arekkw/spark,zeroflag/spark,stylismo/spark,rokusr/spark,jacek99/spark,martylamb/spark,hendrosteven/spark,ganger85/spark,alexlondon07/spark,tempbottle/spark-1,Ariel-Isaacm/spark,universsky/spark-1,MouettE-SC/spark,perwendel/spark,zeroflag/spark,nkhuyu/spark-1,ganger85/spark,PYangDizzle/Spark,opsonsy/spark,Tradunsky/spark,guilhermehbueno/spark,MouettE-SC/spark,stylismo/spark,perwendel/spark,nacx/spark,borud/spark,gutobortolozzo/spark,despegar/spark,MouettE-SC/spark,gimlet2/spark,Tradunsky/spark,greyheart/spark,xdcrafts/spark,mugizico/spark,ztx1491/spark,gimlet2/spark,PYangDizzle/Spark