Homebrew recipe 498

Fixes #498 (with https://github.com/ClusterHQ/homebrew-flocker/pull/1)
The brew manpage suggests using `brew test` after the install

```
       test [--devel|--HEAD] formula
              A  few  formulae  provide  a  test  method.  brew test <formula> runs this test
              method. There is no standard output or return code,  but  it  should  generally
              indicate to the user if something is wrong with the installed formula.

              To test the development or head version of a formula, --devel or --HEAD must be
              passed.,

              Example: brew install jruby && brew test jruby
```