Updated RubyGems to 2.2.2.

RubyGems 2.2.2 installed

=== 2.2.1 / 2014-01-06

Bug fixes:

* Platforms in the Gemfile.lock GEM section are now handled correctly.  Bug
  #767 by Diego Viola.
* RubyGems now displays which gem couldn't be uninstalled from the home
  directory.  Pull request #757 by Michal Papis.
* Removed unused method Gem::Resolver#find_conflict_state.  Pull request #759
  by Smit Shah.
* Fixed installing gems from local files without dependencies.  Issue #760 by
  Arash Mousavi, pull request #764 by Tim Moore.
* Removed TODO about syntax that works in Ruby 1.8.7.  Pull request #765 by
  Benjamin Fleischer.
* Switched Gem.ruby_api_version to use RbConfig::CONFIG['ruby_version'] which
  has the same value but is overridable by packagers through
  --with-ruby-version= when configuring ruby.  Bug #770 by Jeremy Evans.
* RubyGems now prefers the bundler API for `gem install` to reduce HTTP
  requests.  (This change was intended for RubyGems 2.2.0 but was missed.)
  This should address bug #762 by Dan Peterson and bug #766 by mipearson.
* Added Gem::BasicSpecification#source_paths so documentation or analysis
  tools can work properly as require_paths no longer returns extension source
  directories.  Bug #758 Vít Ondruch.
* Gem.read_binary can read read-only files again.  This caused file://
  repositories to stop working.  Bug #761 by John Anderson.
* Fixed specification file sorting for Ruby 1.8.7 compatibility.  Pull
  request #763 by James Mead
Updated Changelog.
Bumped version to 2.2.5.
Reset release date.