Firefox NL: Switch to versioned download

Casks/firefox-nl.rb

@@ -1,8 +1,8 @@
 cask :v1 => 'firefox-nl' do
-  version :latest
+  version '40.0.3'
-  sha256 :no_check
+  sha256 '4ebca181b5dd79cd5a4188b486e848469c36ee78680fe95566cecb358b44724d'
 
-  url 'https://download.mozilla.org/?product=firefox-latest&os=osx&lang=nl'
+  url "https://download.mozilla.org/?product=firefox-#{version}-SSL&os=osx&lang=nl"
   name 'Firefox'
   name 'Mozilla Firefox'
   homepage 'https://www.mozilla.org/nl/firefox/desktop'