Implementing templatable exception type

This pull requests implements generic templates for exceptions implemented in psalm phpstan/phpdoc-parser#51

Author: adrianpanicek

src/Option.php

@@ -40,10 +40,13 @@ abstract public function isNone(): bool;
     /**
      * Unwraps a result, yielding the content of a Some.
      *
+     * @template E of Exception
      * @param Exception $msg
+     * @psalm-param E $msg
      * @return mixed
      * @psalm-return T
      * @throws Exception the message if the value is a None.
+     * @phpstan-throws E
      */
     abstract public function expect(Exception $msg);