v1.2.1

 - **No library logic changes in comparison to v1.2.0**
 - Improved `dist` archive size slightly by improving `.gitattributes`
 - Changed code style to PSR-2
 - Upgraded PHPUnit

 - Added `$maxSize` option for `ArrayCache`.

 - Add `NullCache`.

Release v1.0.0.

Fix tests for PHP 5