Add cask for Chromatic version 0.2.3
user
```ruby
class Chromatic < Cask
  url 'http://download.mrgeckosmedia.com/Chromatic.zip'
  homepage 'https://mrgeckosmedia.com/applications/info/Chromatic'
  version '0.2.3'
  sha1 '5b28e43f89480d339a5f323c2650a2d4a2b5d487'
  link 'Chromatic.app'
end
```
assistant