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

I think this is ready to go. Will you guys take a look and try this out?  Some important points, 1.) You'll need to create files from the .example files (`rake bootstrap:de_example bootstrap:setup_secret` can automate that step). 2.) If you're using parallel tests, you'll need to setup your DB env accordingly (see: https://github.com/grosser/parallel_tests#setup-for-rails). Guard, Parallel Tests, and Zeus seem to be getting along nicely for me.

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Commit description below:

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