Rq-dashboard

* 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

- Mark as incompatible with RQ 1.0 (see 172 for details)
- Add first/last page links to pagination (Thanks Yeray Diaz Diaz)
- Fix 404 errors in docker (Thanks skullY)
- Add confirm modal for dangerous action (Thanks Gerard Sole)
- Enable copy-paste in Jobs table (Thanks Gerard Sole)
- Drop support for EOL Python 2.6 (Thanks Hugo)
- Add Cache-Control header to API
- Update jquery version (Thanks caub)

* Display current job in tooltip in workers list. Thanks Daniel Hnyk
* Allow to specify return URL through get parameters for external systems integration. Thanks Radomirs Cirskis
* Add tests to packages ignore list. Thanks kitsuyui