Skip AsyncFunctionDef test on 3.6

Author: cdce8p

tests/unittest_nodes_position.py

@@ -1,7 +1,10 @@
 import textwrap
 from typing import List
 
+import pytest
+
 from astroid import builder, nodes
+from astroid.const import PY37_PLUS
 
 
 class TestNodePosition:
@@ -104,6 +107,13 @@ def e():  #@
         assert e.position == (14, 0, 14, 5)
 
     @staticmethod
+    @pytest.mark.skipif(
+        not PY37_PLUS,
+        reason=(
+            "Tokenize doesn't support async keyword for Python 3.6,"
+            "only reserved keyword in 3.7"
+        ),
+    )
     def test_position_async_function() -> None:
         """Position should only include keyword and name.