Athletic performance tests integration

As of polyfractal/athletic#5, this PR introduces the Athletic performance test framework into the test runs

 - [x] Implement athletic events
 - [x] Remove old performance tests
 - [x] Compare with `Zend\Stdlib\Hydrator`
 - [ ] Depends on zendframework/zf2#4919
 - [x] Depends on polyfractal/athletic#9
 - [ ] Depends on next stable release of zf2
 - [x] Depends on next stable release of athletic