Does not work with a `namespace()` method name

[aocneanu]

Q	A
Bug report?	yes
Feature request?	no
Library version	1.11.1

Hello,

If I use insights on a class that has a method called namespace() the following error is thrown

Symfony\Component\Debug\Exception\FatalThrowableError  : Argument 1 passed to NunoMaduro\PhpInsights\Domain\Collector::addNamespace() must be of the type string, bool given, called in /Users/adi/code/enso/vendor/nunomaduro/phpinsights/src/Domain/Analyser.php on line 166

Thank you for this awesome package!

[50bhan]

@olivernybroe I think this issue can be closed, right?