Add sleep to avoid bucket rate limit (#2136)

Author: engelke

storage/cloud-client/bucket_policy_only_test.py

@@ -28,6 +28,7 @@ def bucket():
  bucket_name = 'bucket-policy-only-' + str(int(time.time()))
  bucket = client.create_bucket(bucket_name)
  yield bucket
+ time.sleep(3)
  bucket.delete(force=True)