Added support script to check if Python >= 3.6 is available.
Added support script to check if Python >= 3.6 is available.

Review: https://reviews.apache.org/r/67247/

gsantovena/mesos,jpeach/mesos,abudnik/mesos,gsantovena/mesos,andschwa/mesos,andschwa/mesos,jpeach/mesos,kaysoky/mesos,kaysoky/mesos,gsantovena/mesos,dforsyth/mesos,dforsyth/mesos,Gilbert88/mesos,jpeach/mesos,chhsia0/mesos,andschwa/mesos,chhsia0/mesos,Gilbert88/mesos,andschwa/mesos,reneploetz/mesos,Gilbert88/mesos,chhsia0/mesos,reneploetz/mesos,chhsia0/mesos,jpeach/mesos,kaysoky/mesos,gsantovena/mesos,reneploetz/mesos,reneploetz/mesos,dforsyth/mesos,abudnik/mesos,andschwa/mesos,abudnik/mesos,dforsyth/mesos,abudnik/mesos,jpeach/mesos,chhsia0/mesos,abudnik/mesos,jpeach/mesos,gsantovena/mesos,gsantovena/mesos,abudnik/mesos,kaysoky/mesos,kaysoky/mesos,reneploetz/mesos,chhsia0/mesos,dforsyth/mesos,kaysoky/mesos,andschwa/mesos,reneploetz/mesos,dforsyth/mesos,dforsyth/mesos,jpeach/mesos,abudnik/mesos,Gilbert88/mesos,kaysoky/mesos,reneploetz/mesos,andschwa/mesos,Gilbert88/mesos,Gilbert88/mesos,gsantovena/mesos,chhsia0/mesos,Gilbert88/mesos