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
This one was confusing for me to write, so I would like to get many more sets of eyes on it, but I get what you are saying, primarily because just taking `private` as an example:

```
irb(main):004:0> Repo.where(active: true, private: nil).count
   (2.8ms)  SELECT COUNT(*) FROM "repos" WHERE "repos"."active" = 't' AND "repos"."private" IS NULL
=> 156
irb(main):005:0> Repo.where(active: false, private: nil).count
   (34.7ms)  SELECT COUNT(*) FROM "repos" WHERE "repos"."active" = 'f' AND "repos"."private" IS NULL
=> 16601
```

So the first group of `true`s will be set to false, then once that is complete, they will be indistinguishable from the 16601 which are all `false`.

Yes I agree, this is not a reversible migration (this was my first gut feeling). Made the change in b38a62d