Switch to using gitlab styles

The gitlab rubopcop rules that we had previously based ours on has been pulled out into a seperate gem so we are able to re-use it and keep more up to date without having to handle so many of our own rules

In order to do this update I:

1. Ensured current rubocop run was not producing errors
2. Deleted our rubocop file and ran rubocop --auto-gen-config to have rubocop interpret our errors as exceptions with TODOs and give me a minimal rubocop file that was passing
3. Brought in gitlab-styles
4. Turned off rails and rspec cops right away, rails will stay off, rspec there were so many that I want to tackle them later in a seperate MR
5. Run rubocop -a to get as many free fixes as possible
6. Go through each of the remainders and either add exceptions or fix the problems
7. Now that rubocop is passing again. Remove the rubocop-todo file and run rubocop --auto-gen-config to produce our new list of exceptions and TODOs to followup with.