Only upgrade py3-distlib
Only upgrade py3-distlib

https://travis-ci.org/github/collivier/functest/jobs/715442363

Change-Id: Ie34cae67df56b23581e90488c5fa70757efc4b61
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest