removed init so that the image ships no longer ships with an identity.
TODO Maybe allow `ipfs --init run`? It's important to keep the initialization process simple.
The default Docker build creates a daemon.
TODO allow bootstrap node to be overridden at runtime (perhaps with an
environment variable), so we can use custom topologies in test
environments. NB: We still want the default behavior to connect to Mars.
TODO create a docker image that mounts and uses shared volume to make
that mount accessible on the host.
