Using assertSame to let assert equal be restricted

[peter279k]

Changed log

• As title, it should use the assertSame to let assert equals be restricted.

[coveralls]

Coverage increased (+0.0003%) to 99.892% when pulling 3c13502 on peter279k:assertion_enhancement into 3d7ea05 on slimphp:4.x.

[akrabat]

Thanks!