fix flake8 error
diff --git a/atmosphere/operator/controllers/cloud.py b/atmosphere/operator/controllers/cloud.py
index 5d99f11..6f77e8f 100644
--- a/atmosphere/operator/controllers/cloud.py
+++ b/atmosphere/operator/controllers/cloud.py
@@ -7,7 +7,6 @@
 
 from atmosphere import clients, flows
 from atmosphere.models import config
-from atmosphere.operator import tasks
 from atmosphere.operator.api import Cloud