update drone config

.drone.yml

@@ -50,11 +50,6 @@ steps:
     event:
     - push
 
-volumes:
-- name: cache
-  host:
-    path: /pip-cache
-
 - name: sync_argo
   # stage: .post
   image: python:alpine
@@ -86,4 +81,9 @@ volumes:
     branch:
     - master
     event:
-    - push
+    - push
+
+volumes:
+- name: cache
+  host:
+    path: /pip-cache