Vanilla Phoenix app

This app was built by following the steps in doc/howto_rebuild.md. Last built 2020-02-12.

How to branch a new app based on this vanilla template:

• git clone git@github.com:topherhunt/vanilla_phx.git my_folder_name
• cd my_folder_name
• git remote remove origin
• find & replace all uses of "Vanilla" and "vanilla" with your app's name
• rename folders & files in lib/ and test/ as above
• Create secrets.exs from secrets.exs.template. Fill it in as relevant.
• mix deps.get
• mix ecto.create
• mix ecto.migrate
• mix test - around 30 tests should run; all should pass

TODO

• Shouldn't login_tries be indexed on [email, inserted_at] instead of just inserted_at?