Add an OEP-2 compliant openedx.yaml file

[cpennington]

This adds an openedx.yaml file, as described by OEP-2:
http://open-edx-proposals.readthedocs.io/en/latest/oeps/oep-0002.html

The data in this file was transformed from the contents of
edx/repo-tools-data:repos.yaml

[cpennington]

@edx/devops: I'm marking this repo as yours.

[jibsheet]

@cpennington I think @benpatterson and his teams own this?

[cpennington]

@jibsheet: Hrm. It was marked for you guys in @e0d's big spreadsheet-o-repos.

[jibsheet]

@cpennington hmm, ok. Let's see what Ben says. He and his teams have done most of the work on these aside from the work to put them onto the sandboxes which we did because it involved that complicated jenkins job.

[benpatterson]

tagging it with tools and putting edx/testeng makes sense to me. (i wish we had edx/tools btw, which would make more sense in this case...at least to me.)

[jibsheet]

Annoyingly, it doesn't look like we can just make a tools group and put testeng as a member, we'd have to maintain the lists together. That can happen if you prefer, ITSUPPORT is the right JIRA queue.

[cpennington]

It appears that we can rename the team (although it won't update old mentions).

I'll change the owner on this repo.