journald: prepare to release v0.2.0

[hawkw]

0.2.0 (October 22, 2021)

This release updates the tracing-subscriber dependency to v0.3.x.

[hawkw]

ah, looks like we need @Ralith to release this!

   Uploading tracing-journald v0.2.0 (/home/eliza/Code/tracing/tracing-journald)
error: failed to publish to registry at https://crates.io

Caused by:
  the remote server responded with an error: this crate exists but you don't seem to be an owner. If you believe this is a mistake, perhaps you need to accept an invitation to be an owner before publishing.