feat(store): add deis-store component

This is the deis-store component described in https://github.com/deis/deis/issues/1384.
It uses Ceph as a backing service, which gives us the flexibility to
use mounted devices or a blob store gateway.

TESTING: build, install, and start the stores
```console
$ make -C store build
$ make install-stores start-stores
```

If you make changes and want to restart stores:
```console
$ make -C store stop build
$ make start-stores
```