docker: fix type issue (#3491)

* fix type issue

* fix type issue for 'volumes-from'

cloud/docker/docker.py

@@ -1848,12 +1848,12 @@ def main():
             ports           = dict(required=False, default=None, type='list'),
             publish_all_ports = dict(default=False, type='bool'),
             volumes         = dict(default=None, type='list'),
-            volumes_from    = dict(default=None),
+            volumes_from    = dict(default=None, type='list'),
             links           = dict(default=None, type='list'),
             devices         = dict(default=None, type='list'),
-            memory_limit    = dict(default=0),
+            memory_limit    = dict(default=0, type='int'),
-            memory_swap     = dict(default=0),
+            memory_swap     = dict(default=0, type='int'),
-            cpu_shares      = dict(default=0),
+            cpu_shares      = dict(default=0, type='int'),
             docker_url      = dict(),
             use_tls         = dict(default=None, choices=['no', 'encrypt', 'verify']),
             tls_client_cert = dict(required=False, default=None, type='path'),