Upgrade/Update rubocop

Now that almost all of the rubocop blueprints have been completed, make
one final pass through all of the cookbooks ensuring they're all in
sync with each other.

- Upgrade rubocop to 0.18.1
- Fix violations caused by 0.18.1 upgrade
- Move Excludes for non-existent folders to Includes so they
  automatically cover future additions

Change-Id: I00254b346718c1c70e8ad6f8b97e4dbf3f56396f
Implements: blueprint lint-and-unit-testing-for-havana
Use version 3 of the yum cookbook

The 3rd verison of the yum cookbook introduces breaking changes,
so all cookbooks that use it need to be modified.

blueprint yum-cookbook-v3-support

Change-Id: I65f8d3f49816805b0a2d04ef84432b4facc5eb2a
Merge "Use version 3 of the yum cookbook"