Merge branch 'feature/add-background-image-to-mastoapi' into 'develop'

AccountView: Add user background.

See merge request pleroma/pleroma!1280

diff --cc CHANGELOG.md
index 89e8adb41a5646e2add16fcd90fd74f9dfa7bfb3,11f041bdb3f9359d89bdb521fd6f7947ed9a54bb..86d40d898af72bd7b82c8e1afda35a224906d4cb
--- 1/CHANGELOG.md
--- 2/CHANGELOG.md
+++ b/CHANGELOG.md
@@@ -39,8 -37,8 +39,9 @@@ The format is based on [Keep a Changelo
  - Admin API: added filters (role, tags, email, name) for users endpoint
  - Admin API: Endpoints for managing reports
  - Admin API: Endpoints for deleting and changing the scope of individual reported statuses
 +- Admin API: Endpoints to view and change config settings.
  - AdminFE: initial release with basic user management accessible at /pleroma/admin/
+ - Mastodon API: Add background image setting to update_credentials
  - Mastodon API: [Scheduled statuses](https://docs.joinmastodon.org/api/rest/scheduled-statuses/)
  - Mastodon API: `/api/v1/notifications/destroy_multiple` (glitch-soc extension)
  - Mastodon API: `/api/v1/pleroma/accounts/:id/favourites` (API extension)

diff --cc lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
Simple merge

diff --cc test/web/mastodon_api/mastodon_api_controller_test.exs
Simple merge