Use import from six.moves to import the httplib module

The name of the httplib module is http.client instead of
httplib in Python3.

Change-Id: I52a95ea2ff005c2ffbd13d6650367fe80329ce46
Fixes typo error in Rally - orchestrator/api.py

This submission is to fix the typo error
in "rally/orchestrator/api.py" file.
The typo "finised" is being changed to
"finished".

Change-Id: I53798fdf0f08694b6bb463a11fa9c88baaeb94d7
Merge "Use import from six.moves to import the httplib module"