Revert "Merge pull request #1 from theodi/bugfix-use-right-ruby-and-gemset"

This reverts commit d2458f6c18cfbe28b47585e6aba08def506b2f7c, reversing
changes made to edbd66a56bdb83b65ad04a2aa0918bbcc68c9169.

Erk. So that didn't work. I get the error:

    RVM is not a function, selecting rubies with 'rvm use ...' will not work.

    You need to change your terminal emulator preferences to allow login shell.
    Sometimes it is required to use `/bin/bash --login` as the command.
    Please visit https://rvm.io/integration/gnome-terminal/ for a example.

This is fixable though. Will have a crack after lunch.