[tor-relays] Version 0.3 of obfs4 bridge docker image released

[Philipp Winter]

We recently released version 0.3 of our obfs4 bridge docker image.  To
upgrade to the new image or deploy a new container from scratch, please
take a look at our instructions:
<https://community.torproject.org/relay/setup/bridge/docker/>

Here's what changed in our new version:

* We added a new script, 'get-bridge-line', which prints your bridge
  line.  Run it as follows:

    docker exec CONTAINER_ID get-bridge-line

* We improved our setup instructions.  As part of this, we added a
  Makefile that facilitates the process of deploying a container.  Here
  are the new instructions:
  <https://community.torproject.org/relay/setup/bridge/docker/>

* Our new Makefile uses docker volumes to persistently store tor's data
  directory.  This means that you can now upgrade to future docker
  images (which involves deleting your existing container) while keeping
  your bridge's identity.

* We made tor log to stdout in addition to its log file, so the
  following command now shows tor's entire log output, and not just
  the first few lines.

    docker logs $CONTAINER_ID

* The bridge can now bind to obfs4 ports < 1024.

* One can now run multiple bridge containers on a single machine.
  Thanks to thymbahutymba for providing a great template for our
  Makefile and for suggesting docker volumes.

Cheers,
Philipp