Added cask for OmegaT 4.1.0 (Beta) (#3341)

* Added cask for OmegaT 4.1.0 (Beta)

Created a cask for OmegaT 4.1.0 Beta with a special target for “OmegaT
Development”, enabling it to be run concurrently with the stable.

* Update omegat-dev.rb

* Add sha

* Update omegat-dev.rb

Casks/omegat-dev.rb

@@ -0,0 +1,17 @@
+cask 'omegat-dev' do
+  version '4.1.0'
+  sha256 '32ecddcf71a92973bb3578d009aadfac762742df9b7eacf2cc60c75251f84762'
+
+  # downloads.sourceforge.net/omegat was verified as official when first introduced to the cask
+  url "https://downloads.sourceforge.net/omegat/OmegaT%20-%20Latest/OmegaT%20#{version}/OmegaT_#{version}_Beta_Mac_Signed.zip"
+  appcast 'https://sourceforge.net/projects/omegat/rss?path=/OmegaT%20-%20Latest',
+          checkpoint: 'cb4a14253651e4e411a07161493400a78880897bb0e162eb62130b415f400fd8'
+  name 'OmegaT Development'
+  homepage 'http://www.omegat.org/'
+
+  app "OmegaT_#{version}_Beta_Mac_Signed/OmegaT.app"
+
+  caveats do
+    depends_on_java('8+')
+  end
+end