Update Modulefile, CHANGELOG for version 4.1.0

This commit alters the module metadata to indicate a 4.1.0 version
release for the Puppet Forge. It contains backwards compatible
features, refactors and bug fixes.

CHANGELOG updated by JJM
Merge branch 'puppetlabs-release/four_one_oh'

* puppetlabs-release/four_one_oh:
  Update Modulefile, CHANGELOG for version 4.1.0

closes #154