Added remaining tests for new routes

Hello guys, did the tests that makes the new routes "devices" instead of "device" as sugested. Also made the changes that validates if the user.token has been passed as a paramter in the query.

I think we could use an "before_action :validate_user, only: [:list, :last]" and in the method "validate_user" check if the paramter is passed and if the token is valid before returning anything else.