Fix the module full path when using foreign key in tests

Author: aerostitch

pylint_django/tests/input/func_noerror_foreign_key_package.py

@@ -7,7 +7,7 @@
 
 
 class Book(models.Model):
-    author = models.ForeignKey(to='input.Author', on_delete=models.CASCADE)
+    author = models.ForeignKey(to='pylint_django.tests.input.Author', on_delete=models.CASCADE)
 
     def get_author_name(self):
         return self.author.id