Add new cask for AirParrot
user
```ruby
class Airparrot < Cask
  url 'http://download.airsquirrels.com/AirParrot/Mac/AirParrot.dmg'
  homepage 'http://www.airsquirrels.com/airparrot/'
  version '1.5.3'
  sha1 '94449aa750077ccd244959d9e092bd4f3c6c65c3'
  link 'AirParrot.app'
end
```
assistant