[completes #53556821] refine test env by using guard, parallel tests, and zeus

 - Added database_cleaner gem to the :development, :test group to play
nice with Zeus. Alphabetized the listing of the gems in the dev
and test groups.

 - Added guard-livereload to automatically reload your browser window when
you modify and save a view file.

 - Added parallel_tests and integrated with Zeus.

 - Setup guard to work with Zeus/Parallel tests.

 - Added and removed some lines from the Guard file to make it more
appropriate to our use case.

 - Modified GC methodology with test suite to shave off a few seconds.

 - Fine-tuned zeus.json file and created an alias for zeus parallel_rspec

 - Ignore user customizable files and rename as .example

 - Adding Guardfile to .gitignore

 - Tweaks to .gitignore.

 - Add .rspec back in.