Version bumps

Thanks to @bdossantos for the changes in this release!

• chruby 0.3.7
• ruby-build 20131122.1
• ruby MRI 1.9.3p484 and 2.0.0p353

Fix chruby-global

Fixes the chruby-global.sh by moving it out of the env.d directory.

Thanks to @charliesome for this one!

First Experimental Release

This release

• Installs chruby
• Installs ruby-build
• Installs ruby versions
• Installs ruby gems for individual versions
• Sets the default/global ruby version

This release does NOT

• Allow you to configure auto version switching
• Make any guarantees about the rbenv-related assumptions in other boxen modules
• Download pre-compiled rubies