Add a cask-file for the InSync.app
user
```ruby
class Insync < Cask
  url 'http://s.insynchq.com/builds/Insync-1.0.11.31522.dmg'
  homepage 'http://insynchq.com/'
  version '1.0.11.31522'
  sha1 'fe311fc627bcba5ee6516a25298ce3514eaae745'
  link 'Insync.app'
end
```
assistant