Magic wormhole call for testing

Wormhole 0.12.0 from @Snapcrafters can be found on the candidate channel, aside from the version bump, there are a couple of other internal changes to what is on stable:

  • migration from Python 2 to 3
  • migration from no base to core20
  • version setting moved to upstream’s versioneer script

Tentative promotion to stable would be 2021-06-15T03:00:00Z

Sending and receiving a text message on Ubuntu 21.04 works.

Sending and receiving a text message on Kubuntu 20.04 works.