Fix Flake8 lint

This removes extra indentation and replace the use of `is` by `==` when
comparing strings

Signed-off-by: Ulysses Souza <ulysses.souza@docker.com>

tests/unit/cli/log_printer_test.py

@@ -193,7 +193,7 @@ class TestConsumeQueue(object):
             queue.put(item)
 
         generator = consume_queue(queue, True)
-        assert next(generator) is 'foobar-1'
+        assert next(generator) == 'foobar-1'
 
     def test_item_is_none_when_timeout_is_hit(self):
         queue = Queue()