Rq-dashboard

Add error message with bind and port on which is it running
Swap DeprecationWarning to UserWarning
Make queues list collapsible
Fix for cancel button for non-queued jobs

*Changes:*
* Hide workers list if there are many than 8 workers
* Properly align page (move workers toggle to header)
* Add a link to rq-dashboard-on-heroku (thanks Paul Melnikow)
* Update dependencies (thanks dependabot)
* Expose dashboard HTTP port 9181 in Dockerfile (thanks Enrico)
* Switch to pytest for running tests
* Add worker's RQ and Python versions to dashboard (for RQ > 1.1, currently from master)
* Convert README to markdown
* Set up test runs against different RQ versions
* Remove requirements.in, we are using dependabot now
* Use rq 1.1.0 by default (in requirements.txt)
* Add favicon

* Remove dependency on default configuration
* Clean up dashboard layout
* Properly sort workers in failed queue
* Add `--verbose` option and use ERROR level by default. Thanks Nicholas Mei.
* Show instances selector only when there are multiple instances
* Clean up Docker image

* Properly handle legacy settings
* Ask for confirmation before cancelling job. Thanks Vincent Prouillet

* Remove unused async parameter in wrapper method signature, which breaks Python 3.7 compatibility

- Make configuration options consistent, all env parameters now start with RQ_DASHBOARD
- RQ 1.0 basic support. Please make sure that dashboard is installed with the same RQ version as your app does.
- Fix jobs table break if name too long. Thanks abawchen
- Sort list of workers. Thanks erikvanzijst
- Fix XSS in queue API. Thanks caub
- Add proper cache-control headers to all html pages. Thanks caub
- Do not leak passwords in rq-instances.json. Thanks yangbh