use pypi package httpretty with version 0.8.10, fix for build break in CI
use pypi package httpretty with version 0.8.10, fix for build break in CI

Closes-Bug: 1525791
Change-Id: Ie2b41fed049baf42a767df70f4f773267b9aa994

rombie/contrail-controller,sajuptpm/contrail-controller,sajuptpm/contrail-controller,tcpcloud/contrail-controller,sajuptpm/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,eonpatapon/contrail-controller,tcpcloud/contrail-controller,nischalsheth/contrail-controller,tcpcloud/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,sajuptpm/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,tcpcloud/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,sajuptpm/contrail-controller,eonpatapon/contrail-controller,tcpcloud/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,tcpcloud/contrail-controller,nischalsheth/contrail-controller,codilime/contrail-controller,rombie/contrail-controller,codilime/contrail-controller,sajuptpm/contrail-controller