Add missing return type to form template class methods.

Author: Artusamak

src/main/resources/fileTemplates/form_type.php

@@ -10,11 +10,11 @@
 
 class {{ class }} extends AbstractType
 {
-    public function buildForm(FormBuilderInterface $builder, array $options)
+    public function buildForm(FormBuilderInterface $builder, array $options) : void
     {
     }
 
-    public function configureOptions(OptionsResolver $resolver)
+    public function configureOptions(OptionsResolver $resolver) : void
     {
     }
 }