Apply puppet-module-skeleton standards

Significant changes:

- Test against Ruby 1.8.7 instead of ruby-head.
- Use puppetlabs_spec_helper.
- Remove manual fixtures.
- Make smoke and system tests available.
- README and CHANGELOG formatting.
Remove a trailing comma for 1.8.7 compat.
Release version 1.0.0

Bumping major version as this is not backwards compatible.