Removes redundant Ruby version check.
Removes extraneous "#!/usr/bin/env ruby" headers; none of these files are being executed directly.
Switches to https://rubygems.org to avoid rubygems whinging.
Bumps mentioned Ubuntu version.
Bumps recommended Ruby version to latest 1.9.3
Moves .rbenv-version to universal .ruby-version file instead.
Merge pull request #13 from damncabbage/housekeeping

Housekeeping