Update package list before installing in CircleCI
Update package list before installing in CircleCI

It currently fails:
https://app.circleci.com/jobs/github/collivier/functest/189

Change-Id: I8d3e2f468c6c44fa2b680f0370100d2bcf786601
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest