Simplify implementation for optionals

Drop the manual parsing code, use regex.

Fix issue nikic#50

If the static route doesn't exist for the given method, try matching
against dynamic ones as well. Allowed methods are now collected from
both static and dynamic routes.

This changes the route data format, so cache is no longer valid --
maybe include a version identifier in the cache file?

Add PHP 7 to Travis

FastRoute 0.3.0

FastRoute 0.2.0

FastRoute 0.1.0