Add SourceTree Beta Cask 2.4b2 (#2338)

Casks/sourcetree-beta.rb

@@ -0,0 +1,37 @@
+cask 'sourcetree-beta' do
+  version '2.4b2'
+  sha256 'cdb858ab1b0b9f5e7805835fa7c5e91b71dc27600af9de85bd3cfbd215dc796d'
+
+  # atlassian.com was verified as official when first introduced to the cask
+  url "https://downloads.atlassian.com/software/sourcetree/SourceTree_#{version}.zip"
+  appcast 'https://www.sourcetreeapp.com/update/SparkleAppcastBeta.xml',
+          checkpoint: '88d3a78632164545cf9e78e3ed07135e8ccc2533f1f2d0c854160df55d8f67a2'
+  name 'Atlassian SourceTree'
+  homepage 'https://www.sourcetreeapp.com/'
+  license :gratis
+
+  auto_updates true
+  depends_on macos: '>= 10.10'
+
+  app 'SourceTree Beta.app'
+  binary "#{appdir}/SourceTree Beta.app/Contents/Resources/stree"
+
+  postflight do
+    suppress_move_to_applications
+  end
+
+  uninstall launchctl: 'com.atlassian.SourceTreePrivilegedHelper2',
+            quit:      'com.torusknot.SourceTreeNotMAS'
+
+  zap delete: [
+                '~/Library/Application Support/SourceTree',
+                '~/Library/Caches/com.torusknot.SourceTreeNotMAS',
+                '~/Library/Preferences/com.torusknot.SourceTreeNotMAS.plist',
+                '~/Library/Preferences/com.torusknot.SourceTreeNotMAS.LSSharedFileList.plist',
+                '~/Library/Saved Application State/com.torusknot.SourceTreeNotMAS.savedState',
+              ]
+
+  caveats do
+    files_in_usr_local
+  end
+end