Bugfix - Route method match

This PR fixes #225.

This changes the way we track method matches to only count a method as being matched if the route is designed to match. That way, when you setup a catch-all it won't consider the method to be matched but not the actual route itself. :+1: 

The tests have been updated to reflect this functionality.

Since this changes the routing logic from v2.0, it should be noted carefully in the [changelog][changelog-doc] and/or [upgrading documentation][upgrading-doc].

[changelog-doc]: https://github.com/chriso/klein.php/issues/171
[upgrading-doc]: https://github.com/chriso/klein.php/issues/172