Fix sync test when localhost on port 80 is binded

- When localhost:80 was binding the tests was trying to connect into it.
- To test you can simply run sudo python -m SimpleHTTPServer 80 which
  should show :

  1.0.0.127.in-addr.arpa - - [06/Aug/2013 14:10:42] code 501, message Unsupported method ('DELETE')
  1.0.0.127.in-addr.arpa - - [06/Aug/2013 14:10:42] "DELETE /a/c/o HTTP/1.1" 501 -

  (the test was passing since 501 would raise ClientException).
  mock delete_object in the fourth test to fix that
- Refactor the code to use mock.patch as well.

Closes-Bug: 1208802
Change-Id: I5ddd4ac3a97879f51cf5883fcfc0fe0f0adaeff6
Merge "Fix sync test when localhost on port 80 is binded"