Minor fixes based on scrutinizer

Author: gossi

src/generator/ModelGenerator.php

@@ -23,6 +23,9 @@ class ModelGenerator {
 
 	/** @var CodeGeneratorConfig */
 	private $config;
+	
+	/** @var Formatter */
+	private $formatter;
 
 	/**
 	 *

src/model/GenerateableInterface.php

@@ -12,6 +12,8 @@ interface GenerateableInterface {
 
 	/**
 	 * Generates docblock based on provided information
+	 * 
+	 * @return void
 	 */
-	public function generateDocblock();
+	public function generateDocblock(): void;
 }