MAJOR REFACTOR - Pull out core Lendger app

I'm going to pull Rails completely out, transforming this repo into a Gem which
will contain the Lendger core functionality (the application). The UI (i.e.,
the DELIVERY MECHANISM) will be its own project.
Merge branch 'remove_rails_and_convert_to_gem'

* remove_rails_and_convert_to_gem:
  MAJOR REFACTOR - Pull out core Lendger app