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

contrib/dokku-installer.py

@@ -10,7 +10,7 @@ import subprocess
 import sys
 import threading
 
-VERSION = 'v0.18.0'
+VERSION = 'v0.18.1'
 
 hostname = ''
 try: