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

docs/assets/versions.json

@@ -15,6 +15,6 @@
     "0.15.5",
     "0.16.4",
     "0.17.9",
-    "0.18.0"
+    "0.18.1"
   ]
 }