Rebuilt to rename pyrpkg to python2-rpkg
Major changes are
* pyrpkg is renamed to python2-rpkg. Meanwhile, the CLI package named
rpkg is not a separate RPM anymore, it is moved to
* Buildroot is remove since EPEL5 is not a target supported
* Remove unused dependent packages curl and openssh-clients.
* Change Group to Development/Libraries as rpkg is a library for
implementing CLI to interact with dist-git and Koji.