message: Post 0.9.15 release changes
diff: # Release Notes
  -## Platform Version 0.9.15 - UNRELEASED
  +## Platform Version 0.9.16 - UNRELEASED
  +
  +## Platform Version 0.9.15 - 2021-12-10
  * Migrate Rust crates to edition 2021 ([#1798](https://github.com/infinyon/fluvio/issues/1798))
  * TableFormat support for JSON array of objects ([#1967](https://github.com/infinyon/fluvio/issues/1967))
  