Fix for pypcap import problem.

JIRA: CSIT-991

This fix forces the downloads of the complete package for all the pip python
packages to be installed on Centos regardless of the Python metadata on
the host.

Change-Id: I9f5b9faf75306c2b0ae34ca640bc5f36811f900c
Signed-off-by: Thomas F Herbert <therbert@redhat.com>