Updated Mesos version in getting started guide.
Updated Mesos version in getting started guide.

Review: https://reviews.apache.org/r/51571/

dforsyth/mesos,yuquanshan/customizedMesos,abudnik/mesos,Gilbert88/mesos,asamerh4/mesos,zmalik/mesos,abudnik/mesos,Gilbert88/mesos,zmalik/mesos,Gilbert88/mesos,zmalik/mesos,chhsia0/mesos,andschwa/mesos,jpeach/mesos,chhsia0/mesos,jpeach/mesos,jpeach/mesos,Aman-Jain-14/customizedMesos,neilconway/mesos,neilconway/mesos,yuquanshan/customizedMesos,jpeach/mesos,Aman-Jain-14/customizedMesos,Gilbert88/mesos,Gilbert88/mesos,dforsyth/mesos,verizonlabs/mesos,abudnik/mesos,dforsyth/mesos,chhsia0/mesos,kaysoky/mesos,craimbert/mesos,verizonlabs/mesos,verizonlabs/mesos,gsantovena/mesos,neilconway/mesos,craimbert/mesos,yuquanshan/customizedMesos,chhsia0/mesos,kaysoky/mesos,reneploetz/mesos,verizonlabs/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,chhsia0/mesos,kaysoky/mesos,reneploetz/mesos,andschwa/mesos,reneploetz/mesos,dforsyth/mesos,andschwa/mesos,chhsia0/mesos,gsantovena/mesos,neilconway/mesos,yuquanshan/customizedMesos,asamerh4/mesos,zmalik/mesos,neilconway/mesos,yuquanshan/customizedMesos,craimbert/mesos,asamerh4/mesos,asamerh4/mesos,andschwa/mesos,asamerh4/mesos,yuquanshan/customizedMesos,gsantovena/mesos,andschwa/mesos,yuquanshan/customizedMesos,abudnik/mesos,jpeach/mesos,gsantovena/mesos,reneploetz/mesos,zmalik/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,Aman-Jain-14/customizedMesos,dforsyth/mesos,neilconway/mesos,gsantovena/mesos,kaysoky/mesos,reneploetz/mesos,zmalik/mesos,abudnik/mesos,dforsyth/mesos,verizonlabs/mesos,andschwa/mesos,neilconway/mesos,gsantovena/mesos,zmalik/mesos,verizonlabs/mesos,abudnik/mesos,dforsyth/mesos,jpeach/mesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,abudnik/mesos,gsantovena/mesos,craimbert/mesos,jpeach/mesos,kaysoky/mesos,Aman-Jain-14/customizedMesos,Gilbert88/mesos,verizonlabs/mesos,kaysoky/mesos,reneploetz/mesos,chhsia0/mesos,craimbert/mesos,kaysoky/mesos,Gilbert88/mesos,andschwa/mesos,reneploetz/mesos