updade from Atlas repo

17-it-generator/tree/step0/test_tree.py

@@ -5,4 +5,4 @@ def test_1_level():
     class One: pass
     expected = ['One']
     result = list(tree(One))
-    assert expected == result 
+    assert expected == result

17-it-generator/tree/step0/tree.py

@@ -8,4 +8,4 @@ def display(cls):
 
 
 if __name__ == '__main__':
-	display(BaseException)
+    display(BaseException)