Explicitly require hiera for Puppet 2.7 compat
Exclude Puppet 2.7 on Ruby 2.0
Allow builds on Ruby 1.9 and 2.0 to fail

Since we're on 1.8.7 for the foreseeable future, allow later Rubies to
fail.
Enable fast finishing
Add Travis CI build status badge
Update version & changelog for release 0.2.0
Remove trailing comma; bad JSON