Release 0.18.1

# History

## 0.18.1

Install/update via the bootstrap script:

```shell
wget https://raw.githubusercontent.com/dokku/dokku/v0.18.1/bootstrap.sh
sudo DOKKU_TAG=v0.18.1 bash bootstrap.sh
```

### New Features

- #3636: @josegonzalez Unify deb and rpm creation code
- #3635: @josegonzalez Upgrade herokuish to 0.5.2

debian/control

@@ -1,5 +1,5 @@
 Package: dokku
-Version: 0.18.0
+Version: 0.18.1
 Section: web
 Priority: optional
 Architecture: amd64