Protected Attributes -> Strong Parameters

This pull request removes the protected attributes gem from the Gemfile and implements strong parameters for every resource in the project. (in addition to refactoring of many controllers and re-aliasing before filters to before action and other minor style changes)
It's an antiquated test; there used to be a view to create equipment objects that default gave the serial a string ("Enter Serial") value (why they didn't use html placeholder I'll never know). So the controller was filtering for that particular string and making sure it was nil. The view was never rendered anywhere, either so I just removed that whole chunk of logic (and its related test)