Fix issues with Unicode compatibility for Py3

HTTP arguments should not be encoded because:
 * requests library does it automatically replacing unicode
   characters with utf-8 sequences
 * on py3 encoding function replaces string with byte array,
   thus breaking keystone client

Closes bug 1398854

Change-Id: I747778259656f1c9803bcf990cdd85f87a77fd1a
Merge "Fix issues with Unicode compatibility for Py3"