Add Ruby 2.1.0 to .travis.yml
Merge pull request #2801 from salimane/pr_ruby_2_1_0

Add Ruby 2.1.0 to .travis.yml
switch to rubygems 2.2 branch
note room name
Ruby 2.1 actually ships with Rubygems 2.2.0
rubygems 1.8.29
rubygems 2.0.14
rubygems 2.2.0