Refactored phly/http#55
Refactored phly/http#55

- Renamed `$schemes` to `$allowedSchemes` and made it an instance
  variable.
- Removed `getSchemes()`.
- Made `isNonStandardPort()` an instance method.
- Modified `filterScheme` to reference `$allowedSchemes` instead of
  `getSchemes()`, and to use that value to create the exception method.
- Updated `isNonStandardPort()` to reference `$allowedSchemes`.

localheinz/zend-diactoros,mtymek/zend-diactoros,jguittard/zend-diactoros,Ocramius/zend-diactoros,mnapoli/zend-diactoros,deepfreeze/zend-diactoros,Maks3w/zend-diactoros