Add end-of-file-fixer hook to pre-commit (#668)

tests/typecheck/models/test_indexes.yml

@@ -8,4 +8,3 @@
         models.Index("foo", name="test", opclasses=["bar"])
         models.Index("foo", name="test", condition=models.Q(foo=1))
         models.Index("foo", name="test", include=["bar"])
-

tests/typecheck/models/test_init.yml

@@ -254,4 +254,4 @@
                     def base_init(cls) -> 'AbstractModel':
                         return cls(text='mytext')
                 class MyModel(AbstractModel):
-                    pass
+                    pass