(MODULES-3240) Remove rspec-puppet version pin
(MODULES-3240) Remove rspec-puppet version pin

Revert the explicit version pin of the rspec-puppet gem. This was
introduced at;

https://github.com/puppetlabs/puppetlabs-wsus_client/commit/0daee85b

puppetlabs/puppetlabs-wsus_client,ferventcoder/puppetlabs-wsus_client