1.2.0

This release doesn't have any new user-facing feature for lightsd but packs a
bunch of fixes and improvements, both in the code but also the documentation and
examples.

However, this release sees the start of a Python client library for lightsd
which you'll find in the clients directory of the lightsd repository. This
library is currently used to build another child project of lightsd: monolight,
an user-interface for the Monome grid. Both project should end up on
PyPi soon.

Also worth noting, is the full continuous integration pipeline that has been
setup behind the scenes. Most of the work for this release went into it. It will
hopefully make it a lot easier to work on lightsd.

Fixes

• Discovery now works properly on computers with multiple network interfaces
  (closes #2);
• Correctly support optional arguments in the JSON-RPC API;
• A couple of crash/security fixes, one being in the jsmn JSON parser which has
  been upgraded to its latest version;
• FreeBSD build (more BSD fixes to come though, see #16);
• get_light_state now returns a valid target for the bulb's label (the bulb
  id) when it doesn't have a label set.