Fix flake8 errors: F841, E265

This commented-out test caused a couple flake8 errors, so get rid of it:
* F841 local variable 'cmd' is assigned to but never used
* E265 block comment should start with '# '

See https://github.com/nvbn/thefuck/pull/563#discussion_r82104360

tests/rules/test_fix_file.py

@@ -227,10 +227,6 @@ def test_get_new_command(mocker, monkeypatch, test):
     mocker.patch('os.path.isfile', return_value=True)
     monkeypatch.setenv('EDITOR', 'dummy_editor')
 
-    cmd = Command(script=test[0], stdout=test[4], stderr=test[5])
-    #assert (get_new_command(cmd, Settings({})) ==
-    #    'dummy_editor {} +{} && {}'.format(test[1], test[2], test[0]))
-
 
 @pytest.mark.parametrize('test', tests)
 @pytest.mark.usefixtures('no_memoize')