added basic user authorization

@RichardBlair 
Updated routing, controllers, and views in adding user authentication to dickbook to match Rails 4.1.1 standards utilizing information from the following resources:

http://railscasts.com/episodes/250-authentication-from-scratch
https://github.com/rails/strong_parameters
and, of course, advice from https://github.com/RichardBlair
```
def setup
  @user = users(:bob)
end

test "#encrypt_password encrypts the password" do
  user = User.new
  user.password = "someFuckingPassword"
  user.encrypt_password

  assert_equal "insert_hash_here", user.password_hash
end
```