Allow tracking of metadata.json.
Switch to using metadata.json vs Modulefile.
Test against our augeasproviders dependency.

Since we depend on domcleal/augeasproviders, we should actually test
against it and not a different source.
Expand Puppet versions tested in Travis-CI.
Fix CDH/gplextras mismatch.

If cdh_version=>'4', then make sure that cg_version=>'4'.
Fixes Github issue #12.
Merge branch 'feature/issue12' into develop
Fix supported PE versions in metadata.json.