Complete sign in and sign out functionality
	- application controller authenticates a logged-in user from session
	- user is logged in upon account creation
	- specs for session login / logout behavior
	- simplified sign in dropdown in navbar
	- Route to destroy session accepts :get as well as :delete
		(the logout link doesn't have proper UJS behavior)
Fixed specs glitch with signin page
Rewrite Rspec integration tests as acceptance tests
	I tested out Cucumber, but I think it's it too wordy and error-prone
	with large projects having many step definitions. Instead I rewrote
	my Rspec integration tests to read more like acceptance tests.
Finish Users CRUD actions; will_paginate; refactored tests
	- Edit page and update action
		Changing your password requires providing the old password
	- More content for user profile page;
		link to edit profile (only visible to that user);
		admin users see email address and delete link
	- List of users (index) with pretty pagination from will_paginate;
		added link to this list on the navbar, only for signed-in users.
	- Delete user action, available only to admin users.
	- Add is_admin column to users model, defaults to false.
	- Application Controller protected methods to determine whether a
		user is signed in, and whether the user is an admin.
		These can be used to restrict access to any controller action.
	- Rethought and reorganized RSPEC TESTS. I won't use Cucumber and
		I won't write feature specs. Instead I'll write integration tests
		that include "story" specs for all important user actions.
		I'm finally staring to feel comfortable with my specs style.
	- Consolidated Rspec tests by moving regular Capybara actions into
		helpers stored in spec/support/utilities.rb.
	- Removed many autogenerated JS and CSS assets that I don't plan to use.
Rewrote User rspecs; better specs to test controller before filters
	- Rewrote the User model specs to better match my current spec style
	- My integration tests were passing, even though a users controller
		before filter was misconfigured. I wrote a helper (visit_with)
		to properly send PATCH, POST, and DELETE requests using Capybara.
		This will help my tests catch incorrect access control setups.