ably 2.17.0 on Node.js NPM

Full Changelog: 2.16.0...2.17.0

What's Changed

Support update and delete operations over realtime connections #2127
Implement message append for realtime and REST #2127
Publish, update, delete, and append methods now return result objects containing message serial/version information #2127
Fix msgpack encoding for multi-byte UTF-8 characters when using the binary protocol browsers #2145
Fix failing of non-sent queued messages when connection enters suspended/failed/closed state #2123
channel.detach() now immediately transitions to detached when the connection is not connected, instead of waiting or erroring #2149