Release Flocker-0.3.2

To test:

```
brew install https://raw.githubusercontent.com/ClusterHQ/homebrew-tap/release/flocker-0.3.2/flocker-0.3.2.rb
brew test flocker-0.3.2
```

Refs 
 * https://clusterhq.atlassian.net/browse/FLOC-1014
 * https://github.com/ClusterHQ/flocker/pull/983