bump rubygems version to ~> 2.0.0
rollback to liquid 2.5.1 for Jekyll 1.1.2 compatability
Merge pull request #17 from github/bump-rubygems-version

Bump rubygems version to ~> 2.0.0
Merge pull request #19 from github/liquid-2.5.1

Rollback to liquid 2.5.1 for Jekyll 1.1.2 compatability
Version bump
Add releases link to readme.
Merge branch 'master' into jekyll-1.2.0