Make bootstrap-ansible script compatible with RHEL
Make bootstrap-ansible script compatible with RHEL

This patch enables the bootstrap-ansible.sh script to also work on RHEL
and other "yum" based Linux distributions.

Change-Id: I3e28f4f4f09e7387c97afc219899bba1927215e8

openstack/openstack-ansible,BjoernT/openstack-ansible,major/openstack-ansible,BjoernT/os-ansible-deployment,weezer/openstack-ansible,bunchc/openstack-ansible,major/openstack-ansible,jpmontez/openstack-ansible,mrda/openstack-ansible,os-cloud/os-ansible-deployment,Logan2211/openstack-ansible,open-switch/infra_openstack-ansible,yanyao/openstack-ansible,cfarquhar/openstack-ansible,yanyao/openstack-deployment-liberty,BjoernT/openstack-ansible,open-switch/infra_openstack-ansible,mrda/openstack-ansible,BjoernT/os-ansible-deployment,bunchc/openstack-ansible,jpmontez/openstack-ansible,mancdaz/openstack-ansible,yanyao/openstack-ansible,jpmontez/openstack-ansible,weezer/openstack-ansible,yanyao/openstack-deployment-liberty,git-harry/os-ansible-deployment,yanyao/newton,jpmontez/os-ansible-deployment,mancdaz/openstack-ansible,yanyao/openstack-deployment-liberty,robb-romans/openstack-ansible,cloudnull/os-ansible-deployment,stackforge/os-ansible-deployment,jpmontez/os-ansible-deployment,openstack/openstack-ansible,os-cloud/os-ansible-deployment,git-harry/os-ansible-deployment,major/os-ansible-deployment,stackforge/os-ansible-deployment,jpmontez/os-ansible-deployment,Logan2211/openstack-ansible,major/os-ansible-deployment,robb-romans/openstack-ansible,yanyao/newton,mrda/openstack-ansible,open-switch/infra_openstack-ansible,cfarquhar/openstack-ansible,cloudnull/os-ansible-deployment,BjoernT/os-ansible-deployment,git-harry/os-ansible-deployment