Merge branch 'cleanup-flake8-once-more' into 'master'

Cleanup flake8 once more

See merge request flatland/flatland!56

flatland/envs/rail_env.py

@@ -25,6 +25,7 @@ class RailEnvActions(IntEnum):
     MOVE_RIGHT = 3
     STOP_MOVING = 4
 
+
 class RailEnv(Environment):
     """
     RailEnv environment class.