Add cask for Open Office.
user
```ruby
class OpenOffice < Cask
  url 'http://sourceforge.net/projects/openofficeorg.mirror/files/stable/3.4.1/Apache_OpenOffice_incubating_3.4.1_MacOS_x86_install_en-US.dmg/download'
  homepage 'http://www.openoffice.org/'
  version '3.4.1'
end

```
assistant