v0.8.3-rc.1

Full Changelog

• consume trailing slash when creating Matrix Client in HS and IS urls
  #526
• Add ignore users API
  #539
• Upgrade to jsdoc 3.5.5
  #540
• Make re-emitting events much more memory efficient
  #538
• Only re-emit events from Event objects if needed
  #536
• Handle 'left' users in the deviceList mananagement
  #535
• Factor out devicelist integration tests to a separate file
  #534
• Refactor sync._sync as an async function
  #533
• Add es6 to eslint environments
  #532