Update previous stable link to 2.0.0-p576

news was added in 48d4d5ec066c523200c4bdb813da15c426ab74c7
Merge pull request #839 from ruby/update-2.0.0-latest-version

Update previous stable link to 2.0.0-p576
downgrade to ruby-2.1.2 , because anvil deploy is not support to ruby-2.1.3 yet
Merge remote-tracking branch 'upstream/master'