Skipped test for Python 3.6 is valid code

[hauntsaninja]

This test fails (if you unskip it) for Python 3.6 and 3.7 (but works for Python 3.8, presumably because of ast.Constant changes?)

@unittest.skipUnless(sys.version_info < (3, 6), "Only works for Python < 3.6")
    def test_integer_parens(self):
        self.check_roundtrip("3 .__abs__()")

The issue is astunparse doesn't add back in the necessary space:

Python 3.6.10 (default, Jan 23 2020, 23:35:52) 
[GCC 4.2.1 Compatible Apple LLVM 11.0.0 (clang-1100.0.33.17)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 3 .__abs__()
3
>>> 3.__abs__()
  File "<stdin>", line 1
    3.__abs__()
            ^
SyntaxError: invalid syntax
>>> import ast
>>> import astunparse
>>> astunparse.unparse(ast.parse("3 .__abs__()"))
'\n3.__abs__()\n'