Fix bare run of func tests

tests/functional/utils.py

@@ -44,6 +44,7 @@ def spawn(request, tag, dockerfile, cmd, install=True, copy_src=False):
 
     def _finalizer():
         proc.terminate()
+        if not bare:
             container_id = subprocess.check_output(['docker', 'ps']) \
                                      .decode('utf-8').split('\n')[-2].split()[0]
             subprocess.check_call(['docker', 'kill', container_id])