remove link to like movie if user is unauthenticated

- create like_link helper method
remove like link from review show page

- move like_link helper to application helper
add authenticate_user! to likes controller
- Add user_id to likes table
- Add user validation to like model
- Create db association for like
- Add likes association to user model
- Add dependent destroy for likes on user model
- Add single like per user functionality
- Define already_liked_by? method in movies_controller
- Add already_liked_by functionality added to reviews
- Add already_liked_by to application_helper
change redirect_back_or_to_default call to pass in /
add parens to indicate method invocation
refactor like_link helper method

- add tests

- pass in user rather than use current_user

- create like factory
move validation options to a second line in user model
fix indentation in user liking movie spec
fix indentation in user liking review spec
use like factory in movie spec
use like factory in review spec
move pry from test to development/test
fix query performance in liked_by_checker
Add parens and update app_helper_spec expectation to be_blank