change readme to note support for 5.0
change readme to note support for 5.0

jusko/rbvmomi,rlane/rbvmomi,10xEngineer/rbvmomi,rlane/rbvmomi,rapid7/rbvmomi,jusko/rbvmomi,omar-infinio/rbvmomi,rcorrieri/rbvmomi,frapposelli/vagrant-rbvmomi,synthead/rbvmomi,logankimmel/rbvmomi,vmware/rbvmomi,10xEngineer/rbvmomi,synthead/rbvmomi,frapposelli/vagrant-rbvmomi,rapid7/rbvmomi