Handle repos with inadequate information

* Inactivate repositories which lack privacy or org information
* Add rake task to update repo information

https://trello.com/c/oPFtmreZ/393-builds-are-being-run-for-active-repos-missing-privacy-and-organization-information
Perhaps I'm thinking about this rollback incorrectly but I'm not sure this SQL is necessarily the inverse of the `up`.

I believe this `down` will set all `repo`'s with `active == false` that have missing info to `active == true` whereas what the `up` is doing is fixing up just the offending records. In other words, I think the `down` is going to set all the `repo`'s with missing info to `active` instead of just a subset of the ones with missing info (as is currently the case).

If the above thinking makes sense, should this migration be irreversible (raise an exception) since once we roll forwards we will no longer know which records were the offending ones (because all `repo`'s with missing info will be `active == false`).

Thoughts? Am I missing something?