Dear Maintainer,

I was attempting to `docker-compose push` to localhost docker registry but it
failed with the message: `ERROR: no basic auth credentials`.

I was unable to `docker login localhost:5000`. Couldn't figure out if there are
default credentials or what they might be.

`sudo service docker-registry status` reported the following when attempting
the push:

`error checking authorization: read /etc/docker/registry: is a directory`

I updated /etc/docker/registry/config.yml to change the `path` option under
`htpasswd` to point to a file instead of a directory (see my altered
configuration file below).

Restarted `docker-registry`, retrieved the user and auto-generated password
from `sudo service docker-registry status`.

Following a `docker login localhost:5000`,
`docker-compose push` now appears to work as expected.