Payout

 - semaphore - added dependency for tagging

Payout

 - fixed typo in semaphore
 - removed clair scan

Revert change to Dockerfile

Download updated user-agent files

Closes plausible#309

Release selfhosted (plausible#341)

* Optimize Dockerfile

* Update selfhosting documentation

* Remove unnecessary files

* Remove internal config stuff

* Update config

* WIP

* Use BASE_URL instead of HOST and SCHEME

* Add port to endpoint url config

* Make config/config.exs on par with config/releases.exs

* Add changelog entry

* Document configuration change