Fix pip3 version issues

The latest pipelines have been failing due to issues
caused by an older version of pip3 while setting up DPDK
in CentOS 7 based deployments. This patch includes an update
to fix it.

Signed-off-by: Rihab Banday <rihab.banday@ericsson.com>
Change-Id: Ie338adaa4908850af25dc65a551b62549d431f81
Reviewed-on: https://gerrit.opnfv.org/gerrit/c/kuberef/+/73224
Tested-by: jenkins-ci <jenkins-opnfv-ci@opnfv.org>
Reviewed-by: Georg Kunz <georg.kunz@ericsson.com>
Reviewed-by: Michael Pedersen <michaelx.pedersen@intel.com>