Avoid exception when superclass is null and no docblock is provided for a method

[meyerbaptiste]

When a class does not have parent and no docblock is provided for a method, Class_::getParent() method returns null so an exception is thrown:

PHP Fatal error:  Uncaught TypeError: Argument 2 passed to Dunglas\PhpDocToTypeHint\Converter::getObject() must be an instance of phpDocumentor\Reflection\Fqsen, null given, called in /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php on line 287 and defined in /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php:325
Stack trace:
#0 /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php(287): Dunglas\PhpDocToTypeHint\Converter->getObject(Object(phpDocumentor\Reflection\Php\Project), NULL, 0)
#1 /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php(425): Dunglas\PhpDocToTypeHint\Converter->getDocBlock(Object(phpDocumentor\Reflection\Php\Project), 0, NULL, 'ElePHPant', '__construct')
#2 /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php(105): Dunglas\PhpDocToTypeHint\Converter->getReturn(Object(phpDocumentor\Reflection\Php\Project), 0, NULL, 'ElePHPant', '__construct')
#3 /Users/meyerb/workspace/phpdoc-to-typehint/src/ConvertCommand.php(90): Dunglas\PhpDocToTypeHint\Converter->convert(Obj in /Users/meyerb/workspace/phpdoc-to-typehint/src/Converter.php on line 325

[dunglas]

Thanks