Log Message:
Update rubygems to 2.0.3.

THere are too many changes to write here, please refer these release notes.

http://blog.rubygems.org/2013/03/11/2.0.3-released.html
http://blog.rubygems.org/2013/03/06/2.0.2-released.html
http://blog.rubygems.org/2013/03/05/2.0.1-released.html
http://blog.rubygems.org/2013/02/24/2.0.0-released.html
http://blog.rubygems.org/2013/02/08/2.0.0.rc.2-released.html
http://blog.rubygems.org/2012/12/03/2.0.0-preview2.html