```ruby
class Zotero < Cask
  url 'http://download.zotero.org/standalone/4.0.16/Zotero-4.0.16.dmg'
  homepage 'http://www.zotero.org/'
  version '4.0.16'
  sha1 '461752e20adb669471063b5ea1c573037d73ada3'
  link 'Zotero.app'
end
```

Update Zotero cask version to 4.0.17.
user
```ruby
class Zotero < Cask
  url 'http://download.zotero.org/standalone/4.0.17/Zotero-4.0.17.dmg'
  homepage 'http://www.zotero.org/'
  version '4.0.17'
  sha1 '470365f88714d72a3ef99d4fb3be8b1cdf881d5d'
  link 'Zotero.app'
end
```
assistant