Updated to match semver and release notes.

Before this update the Modulefile was not following semver in
relation to stable/havana, and the README files were not in sync.
This update introduces proper semver and consistency.

Keystone in fixtures tracks master. Fix modulefile to match
this dependency and be consistent with Horizon dependency

Change-Id: I622ef84b5c50abd1da96a75e9935265cd947ca6a
Merge "Updated to match semver and release notes."
Merge git://github.com/puppetlabs/puppetlabs-keystone