Prophecy Argument tokens should be accepted as values

[Jean85]

Code example:

$mock = $this->prophesize(SomeClass::class);
$mock->giveMeAString(Argument::type('string'))->willReturn();

Argument static methods in Prophecy let us define better and precise expectation. Right now, with this plugin, it gives an alert about type mismatching. It should not show that warning.

[maxfilatov]

@Jean85 thanks, it will be fixed