```ruby
class ThunderbirdBeta < Cask
  version '31.0b3'
  sha256 '82cf13b42f72a660920cfd025220d2ce9ddfb56327b01721b4b02e065752061d'

  url 'https://download-installer.cdn.mozilla.net/pub/thunderbird/releases/31.0b3/mac/en-US/Thunderbird%2031.0b3.dmg'
  homepage 'https://www.mozilla.org/en-US/thunderbird/all-beta.html'

  link 'Thunderbird.app'
end
```

Update Thunderbird Beta to 32.0b1
user
```ruby
class ThunderbirdBeta < Cask
  version '32.0b1'
  sha256 '0f66e9cb452293e248d92c9a156c0b81c50e81ba1107922ab6f8b555934e83d3'

  url 'https://download-installer.cdn.mozilla.net/pub/thunderbird/releases/32.0b1/mac/en-US/Thunderbird%2032.0b1.dmg'
  homepage 'https://www.mozilla.org/en-US/thunderbird/all-beta.html'

  link 'Thunderbird.app'
end
```
assistant