Use MAJOR.MINOR.PATCH version format

Current behaviour of the puppet module tool is to fail if a modules
version does not match the usual X.Y.Z format.

See https://github.com/puppetlabs/puppet/blob/6fa68b54ac621d60dbf1b062f8dd66b186d1a87f/lib/puppet/vendor/semantic/lib/semantic/version.rb#L13-L19
and https://tickets.puppetlabs.com/browse/PUP-2752 for details.
Merge pull request #9 from fadenb/version_fmt_fix

Use MAJOR.MINOR.PATCH version format