Update to gitlab-ci 2.1 branch.

Note there is a bug in the vcsrepo git provider, which stops it from changing branch. To update an existing install you must manually switch branch.
Merge branch 'master' of github.com:lboynton/puppet-gitlab-ci

* 'master' of github.com:lboynton/puppet-gitlab-ci:
  Add modulefile for submitting to the forge