Create ssh-tunnel-manager-beta.rb (#2239)

Casks/ssh-tunnel-manager-beta.rb

@@ -0,0 +1,12 @@
+cask 'ssh-tunnel-manager-beta' do
+  version :latest
+  sha256 :no_check
+
+  # dl.devmate.com/org.tynsoe.sshtunnelmanager was verified as official when first introduced to the cask
+  url 'https://dl.devmate.com/org.tynsoe.sshtunnelmanager/beta/SSHTunnelManager.zip'
+  name 'SSH Tunnel Manager'
+  homepage 'http://projects.tynsoe.org/en/stm/'
+  license :gratis
+
+  app 'SSH Tunnel Manager.app'
+end