Create user support.

Creates model, controller, routes, helper, Javascript file, SCSS file, view
files, database migration, and RSpec files for users. The current user pages
are edit, index, new, and show.

    $ rails generate controller Users edit index new show --no-test-framework
        * app/controllers/users_controller.rb
        * app/views/users/edit.html.haml
        * app/views/users/index.html.haml
        * app/views/users/new.html.haml
        * app/views/users/show.html.haml
        * app/helpers/users_helper.rb
        * app/assets/javascripts/users.js
        * app/assets/stylesheets/users.css.scss
    $ rails generate model User email:string username:string
        * db/migrate/20140925222122_create_users.rb
        * app/models/user.rb
        * spec/models/user_spec.rb
        * spec/factories/users.rb
    - The default files were edited to make them stylistically consistent.
    - Additional RSpec files were created:
        * spec/features/users_features_spec.rb
        * spec/requests/users_requests_spec.rb
        * spec/routing/users_routes_spec.rb
        * spec/views/users_views_spec.rb
    - spec/spec_helper.rb was modified so that users_helper.rb will be included
      in tests.
    - Routes for users were added.
    - Unnecessary .keep files were deleted.
    $ git add -u .
    $ git commit -F commit-message.txt
    $ git push origin master

Tests passing: 5
Tests failing: 0
Add validations and filters to regulate user's information.

Adds validations and filters that will enforce restrictions on a user's email
and username. A username must:

    - Be present;
    - be less than 32 characters;
    - consist of at least one alphanumeric character, spaces, underscores,
      periods, and/or dashes;
    - be unique, even with regard to case and when stripped of spaces,
      underscores, periods, and/or dashes; and,
    - not have spaces at the beginning or end.

An email must:

    - Be present;
    - be unique;
    - be case-insensitive;
    - follow the proper email format; and,
    - be saved in all lower-case.

The uniqueness of the user's name was ensured by adding a database column
called simple_name and requiring its uniqueness.

    - The validations were added to app/models/user.rb.
    - A simple_name column was added to the users table set up by the database
      migration 20140925222122_create_users.rb. Indices and uniqueness were
      added to the email and simple_name columns.
    $ rake db:migrate RAILS_ENV=development
    $ git add .
    $ git commit -F commit-message.txt
    $ git push origin master

Tests passing: 5
Tests failing: 0