Allow a  user_id_by option to use an alt. to #id
Add test for #user_id
Add another test for #user_id
Rename to id_User_by, make Rollout::Feature deal with all of that stuff
Formatting
We need the user_id here too
We shouldn't need to call to_s on these
Refactored tests a bit
Merge branch 'master' of github.com:FetLife/rollout into feature-IdUserBy
Checking for Integer is redundant
Merge pull request #60 from FetLife/feature-IdUserBy

Feature id user by