Static analyzer/Intellisense not happy

[mbolli]

Hi, thanks for this interesting piece of software!

I'm trying to use it in a prototype, but I stumbled on something that would hopefully be easy to fix:

RouteAbstract::add() returns RouteAbstract instead of static -> This means that PhpStan (and PhpStorm) show an error when having e.g.

$routes = Route::add('_controller')
    ->default('login')
    ->group(self::getControllers(...))
;

or

Route::add()->get();

Phpstan errors:

Call to an undefined method Ertuo\RouteAbstract::group(). 
Call to an undefined method Ertuo\RouteAbstract::get().