Link to find similar movies send the id.

Now the link to search movies with the same director make get with
the movies id as a parameter instead of passing the director as
parameter.

The controller was changed to find the movie by id and then retrieve
the director.
Bug fixed: controller should ask for all movies.

Before the controller was asking just for one movie with a given
director. Now it asks correctly for all movies.
Model is totally mocked in the controller spec.

Added new stub to Movie in the spec test.

Also updated the db so that it can be better tested manually.
Implemented the find_similar view