* PLT-7195: Added new config option, new license feature, and config UI to system console. Still need to implement behaviour change in email batching code
* PLT-7195: Modified batch emails to respect email notification content type setting
* PLT-7195: Tweaking the colours a bit
* PLT-7195: Added support for email notification content type setting in immediate (non-batched) notification messages. Attempted to clean up the code somewhat. Unit tests coming in a future commit
* PLT-7195: Added unit tests for non-batched emails
* Checked license when applying email content settings
* Changed return type of getFormattedPostTime
* Fixes Elasticsearch to have consistent capitalisation everywhere
across the code and UI (except the config file unfortunately).
* Adds basic unit tests for Elastichsearch.
* Adds a Elasticsearch docker image to the Makefile to enable testing
the Elasticsearch feature.
* Unit Tests for model/push_response.go
* Unit tests for security_bulletin.go
* Unit tests for webrtc.go
* Unit tests for model/password_recovery.go
* Add missing headers.
* Unit tests for model/license.go
* Tidy up existing tests.
* Simplify JSON to/from tests.
* Fix gofmt
