2.0.0 slight refactor and regression tests

This PR adds unit and system tests as well as changes the following behavior of the module.

* Removes os_maj_version fact in favor of other Facter's operatingsystemmajrelease, other module's os_maj_version or a inline_template as a fallback.
* Cleanup spacing and variables to pass puppet-lint tests
* Also ensure CentOS-Vault.repo and CentOS-SCL.repo are removed
* Ensure all *.repo files are removed after the yumrepo resources
* Ensure all Package resources are run after the yumrepo resources