OSTree Support

At this point only the nightlies for 2.10 and 2.11 should be of interest.

Regardless, I'll check to make sure we don't have systemic problems, and fix them if we do.

I forgot to ref this issue, but this should be fixed with tonight's build. There was a bug in the build script. If it does get fixed, I'll ref the commit and close this.

Alright, I've ref'd the commit with this fix. The main thing was that we have a cancelled build for this version of the OSTree plugin, and the build script was only checking that a build existed in koji, not that the build was completed. Adding in a build result check to ensure a build is actually completed before assuming we can download it got the build script to correctly build ostree once again.