Intall GBP on Mitaka using packstack over centos

Per https://www.rdoproject.org/networking/neutron-gbp one have to "yum install openstack-neutron-gbp" and "yum install python-gbpclient", but these are not included in the regular repositories (found only in fedora).
How can it be installed on Mitaka Centos-Packstack, and also compatible with ODL (beryllium) ?