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.

Change-Id: If4f653a5288b9cca42eb45f5dbd057fd01313a81
Merge "Updated to match semver and release notes."
Merge git://github.com/puppetlabs/puppetlabs-nova