Merge branch 'master' into develop

# By Martin Fenner (32) and waffle.io (1)
* master: (33 commits)
  ALM-567 fixed tests for filters by source
  ALM-419 fixed Facebook tests
  ALM-163 combine score and comments for Reddit event_count
  Change colors of status donut in admin source view to better match the other donuts
  ALM-568 workaround for missing article
  fix asset loading in development mode
  ALM-419 fix typo in Facebook source
  Copernicus API expects DOI not to be escaped. Fixes #23.
  ALM-563 handle malformed JSON from Wordpress.com
  ALM-436 delete queues and queued_at for articles when source is inactivated
  ALM-436 added .env file for foreman configuration
  ALM-567 added scopes to select sources
  ALM-163 combine score and comments in Reddit source
  ALM-567 adding source-specific configuration to filters
  Added documentation for new sources
  Removed new Twitter source from seeds.db. Closes #22.
  ALM-566 don't sleep workers when errors occur
  ALM-565 allow staff users to delete alerts
  ALM-559 added documentation and tests for Wordpress.com source
  added OpenEdition to daily/monthly/yearly stats
  ...
small changes to responsive layout on phones
ALM-436 check disabled status every time a batch job runs
ALM-392 fix increasingTooFast filter
ALM-436 change how we handle disabled sources
Merge branch 'release/v.2.9.7'