Run PHPCS to check PSR2 on PHP files (but exclude kohana files)

Summary:
Since we're enforcing PSR2 on the new code in src/ lets use arclint to make life easier

Run PHPCS to check PSR2 on PHP files (but exclude kohana files)

Test Plan:
- Edit src/Init.php and run `arc lint`, get errors
- Edit some php in application and run `arc lint`, see nothing checked

Reviewers: eyedol, shadowhand

Reviewed By: shadowhand

Differential Revision: https://phabricator.ushahidi.com/D285