roles/kojira: Deploy the Koji repository agent

The *kojira* role sets up the Koji repository agent to manage
repository metadata for build tags. It runs as a daemon, usually on the
same machine as the Koji hub. A client certificate is required for
authentication, and must be supplied by placing it in the
`certs/koji/{{ inventory_hostname }}` directory.

roles/kojira/defaults/main.yml

@@ -0,0 +1,3 @@
+koji_home: /var/lib/koji
+kojihub_host: "{{ ansible_fqdn }}"
+kojihub_url: https://{{ kojihub_host }}/kojihub