The upstream Avion and Decora code has changed to punt retry logic out to
consumers, so update to match. As a bonus, Avion also gains support for
pulling switch configuration off the web rather than requiring manual
configuration.
* avion light: Bump python-avion dependency version
The dependencies in python-avion weren't sufficiently strict. This is now
fixed, but means we need to depend on a new version.
* decora light: Bump python-decora dependency
There's a new version of python-decora with a reliability fix, so depend on
that.
