v0.8.4

Added

• Workflows now support environment variables. These are top-level
  arguments to a workflow. These are then exposed on the execution page
  allowing users to modify the most important variables in a workflow
  without modifying the workflow itself.
• Added a health check endpoint at the /heath endpoint

Changed

• The Metrics page now defaults to showing workflow metrics instead of
  app metrics

Fixed

• Action results and workflow results stream now filter for the
  currently-executing workflow. This eliminates many issues experienced
  by multiple users executing workflows concurrently from the workflow
  editor
• Fixed an error which caused the Scheduler to not execute workflows
• Fixed another bug in the scheduler in which the scheduled workflows
  would not persist across server restarts
• A bug where messages couldn't be sent
• A bug where modifying more than one device at a time on the playbook
  editor would cause the workflow to be invalidated
• Some database configuration bugs when used with non-SQLite databases
• Fixed a bug which wouldn't allow a user to a abort a workflow if it
  was pending execution.