add g++ package and list rvm version
add g++ package and list rvm version

Blackbaud-StacyCarlos/skyux,Blackbaud-LukeJones/skyux,Blackbaud-LukeJones/skyux,Blackbaud-StacyCarlos/skyux,Blackbaud-StacyCarlos/skyux,Blackbaud-LukeJones/skyux