juju-deployer runs into certificate errors with websocket-client 0.44 python/python3 libraries

[Barry Price]

After a recent upgrade in Ubuntu 17.10 (Artful) to python-websocket and python3-websocket 0.44.0-0ubuntu2 (from 0.37.0-2), juju-deployer now crashes with certificate errors on any kind of deploy: http://pastebin.ubuntu.com/25679956/

The above is for a local test Juju 2 controller running on the LXD provider, but I've seem the same error for Openstack and GCE clouds, so it seems to be provider-agnostic.

Downgrading the python-websocket and python3-websocket packages back to 0.37.0-2 solves the problem.

I'm using the latest Zesty build of python3-amulet from the Juju Stable PPA (there's no Artful build yet) and the latest Yakkety build of juju-deployer from the Mojo Stable PPA (likewise).

$ dpkg -l python3-amulet python3-juju-deployer | cat
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=====================-======================================================-============-=======================================================
ii python3-amulet 1.19.0-0ubuntu1~ubuntu17.04.1~ppa2 all Python3 library for the amulet testing harness
ii python3-juju-deployer 0.10.0~bzr208~60~ubuntu17.04.1~bzr210~61~ubuntu16.10.1 amd64 A tool to deploy complex stacks of services using juju.