refactor: optimize imports

Author: weakish

leancloud/__init__.py

@@ -21,15 +21,15 @@
 from .client import use_master_key
 from .client import use_production
 from .client import use_region
-from .conversation import Conversation
+from .conversation import Conversation  # noqa: F401
 from .engine import Engine
 from .engine import LeanEngineError
 from .engine.https_redirect_middleware import HttpsRedirectMiddleware
 from .errors import LeanCloudError
 from .errors import LeanCloudWarning
 from .file_ import File
 from .geo_point import GeoPoint
-from .message import Message
+from .message import Message    # noqa: F401
 from .object_ import Object
 from .push import Installation
 from .query import FriendshipQuery

leancloud/engine/__init__.py

@@ -18,9 +18,9 @@
 from . import utils
 from . import leanengine
 from .authorization import AuthorizationMiddleware
-from .cookie_session import CookieSessionMiddleware
+from .cookie_session import CookieSessionMiddleware  # noqa: F401
 from .cors import CORSMiddleware
-from .https_redirect_middleware import HttpsRedirectMiddleware
+from .https_redirect_middleware import HttpsRedirectMiddleware  # noqa: F401
 from .leanengine import LeanEngineApplication
 from .leanengine import LeanEngineError
 from .leanengine import after_delete

leancloud/sys_message.py

@@ -10,8 +10,6 @@
 from __future__ import unicode_literals
 
 import arrow
-
-import leancloud
 from leancloud.object_ import Object