Add Firefox Aurora and Nightly

Casks/firefox-aurora.rb

@@ -0,0 +1,7 @@
+class FirefoxAurora < Cask
+  url 'https://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla-aurora/firefox-27.0a2.en-US.mac.dmg'
+  homepage 'http://www.mozilla.org/en-US/firefox/aurora/'
+  version '27.0a2'
+  no_checksum
+  link 'FirefoxAurora.app'
+end

Casks/firefox-nightly.rb

@@ -0,0 +1,7 @@
+class FirefoxNightly < Cask
+  url 'http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/firefox-28.0a1.en-US.mac.dmg'
+  homepage 'http://nightly.mozilla.org'
+  version '28.0-alpha1'
+  sha1 'no_checksum'
+  link 'FirefoxNightly.app'
+end