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