Install python2 for Ubuntu 16.04 and CentOS 7 in Vagrant
Install python2 for Ubuntu 16.04 and CentOS 7 in Vagrant

Install python2 for Ubuntu 16.04 and CentOS 7 before executing test
script.

Change-Id: I3bf0ec773316304f6bce5905cd041ea72bd16fc3

os-cloud/openstack-ansible-pip_install,openstack/openstack-ansible-pip_install,openstack/openstack-ansible-pip_install,os-cloud/openstack-ansible-pip_install