sitespeed.io 14.2.1

on Node.js NPM

• Updated to Firefox 79 in the Docker slim container and in the default container.
• Add unit to Slack summary, thank you Lise Bilhaut for PR #3102.
• Let GCS and S3 send a setup message on startup so other plugins knows that they are configured #3101.

v14.1.0...v14.2.1