basic font colors, families, sizes
css for displaying menu, headers
rendering partial for anonymous menu
created sessions controller with new, create, destroy routes to log users in and out (pending testing of user authentication)
added link_to paths for signup/login to anonymous user menu
added gems for better errors and rails console:
compress validations for uniqueness to one line; added requirement for presence of password for has_secure_password
ability to logout added to nav menu
sessions controller with functional signing in and out
users controller updated for signing up users and creating a new session
Merge branch 'users_create_questions' of https://github.com/feministy/stack_overflow into users_create_questions

Conflicts:
	app/controllers/sessions_controller.rb