Description of problem:
Nightly repo in COPR does not contain yum-rhn-plugin. When installing spacewalk-postgresql on RHEL6, this results in:

=====
--> Processing Conflict: rhn-client-tools-2.7.16-1.el6.noarch conflicts yum-rhn-plugin < 1.6.4-1
--> Finished Dependency Resolution
Error: rhn-client-tools conflicts with yum-rhn-plugin-0.9.1-60.2.el6_8.noarch
Error: Package: rhn-check-2.7.16-1.el6.noarch (group_spacewalkproject-nightly)
           Requires: yum-rhn-plugin >= 1.6.4-1
           Installed: yum-rhn-plugin-0.9.1-60.el6.noarch (@anaconda-RedHatEnterpriseLinux-201604140956.x86_64/6.8)
               yum-rhn-plugin = 0.9.1-60.el6
           Available: yum-rhn-plugin-0.9.1-5.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-5.el6
           Available: yum-rhn-plugin-0.9.1-7.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-7.el6
           Available: yum-rhn-plugin-0.9.1-26.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-26.el6
           Available: yum-rhn-plugin-0.9.1-26.el6_1.1.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-26.el6_1.1
           Available: yum-rhn-plugin-0.9.1-36.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-36.el6
           Available: yum-rhn-plugin-0.9.1-40.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-40.el6
           Available: yum-rhn-plugin-0.9.1-43.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-43.el6
           Available: yum-rhn-plugin-0.9.1-45.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-45.el6
           Available: yum-rhn-plugin-0.9.1-48.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-48.el6
           Available: yum-rhn-plugin-0.9.1-49.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-49.el6
           Available: yum-rhn-plugin-0.9.1-50.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-50.el6
           Available: yum-rhn-plugin-0.9.1-52.el6_6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-52.el6_6
           Available: yum-rhn-plugin-0.9.1-52.3.el6_6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-52.3.el6_6
           Available: yum-rhn-plugin-0.9.1-58.el6.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-58.el6
           Available: yum-rhn-plugin-0.9.1-60.2.el6_8.noarch (rhel-6-server-rpms)
               yum-rhn-plugin = 0.9.1-60.2.el6_8
=====

Version-Release number of selected component (if applicable):
RHEL6, SW nightly

How reproducible:
Deterministic

Steps to Reproduce:
1. Follow HowToInstallNightly docs and as SW nightly repo file, wget https://copr.fedorainfracloud.org/coprs/g/spacewalkproject/nightly/repo/epel-6/group_spacewalkproject-nightly-epel-6.repo
2. # yum install spacewalk-postgresql

Actual results:
Error shown above

Expected results:
Successfully installed spacewalk-postgresql with dependencies