Use HTTPS for Rubygems

It is now recommended to use HTTPS for connecting to Rubygems.
Merge pull request #1291 from stevenharman/patch-1

Use HTTPS for Rubygems
Merge remote-tracking branch 'upstream/master'
Revert "Updating .rvmrc for ruby 2.0.0"

Probably a bad idea to push this forward blindly...

This reverts commit 2ea008e182633d05ce443b57f4d590f0f576ca65.