use default values epel-6-x86_64 nosnap notag sign if not define as params
do not fail when no tag found, tag is not required for nontag builds
when using nullglob escape globs to propagate wildcars to subcommand
Merge branch 'master' into github

* master:
  when using nullglob escape globs to propagate wildcars to subcommand
  do not fail when no tag found, tag is not required for nontag builds
  use default values epel-6-x86_64 nosnap notag sign if not define as params