Release 0.18.4

# History

## 0.18.4

Install/update via the bootstrap script:

```shell
wget https://raw.githubusercontent.com/dokku/dokku/v0.18.4/bootstrap.sh
sudo DOKKU_TAG=v0.18.4 bash bootstrap.sh
```

### Other

- #3703: @scjody Update DOKKU_SCALE from Procfile during ps:scale

docs/getting-started/install/docker.md

@@ -3,7 +3,7 @@
 Pull the dokku/dokku image:
 
 ```shell
-docker pull dokku/dokku:0.18.3
+docker pull dokku/dokku:0.18.4
 ```
 
 Next, run the image.
@@ -17,7 +17,7 @@ docker run \
   --publish 8443:443 \
   --volume /var/lib/dokku:/mnt/dokku \
   --volume /var/run/docker.sock:/var/run/docker.sock \
-  dokku/dokku:0.18.3
+  dokku/dokku:0.18.4
 ```
 
 Dokku is run with the following options: