frege-repl: depend on openjdk

Formula/frege-repl.rb

@@ -4,16 +4,16 @@ class FregeRepl < Formula
   url "https://github.com/Frege/frege-repl/releases/download/1.4-SNAPSHOT/frege-repl-1.4-SNAPSHOT.zip"
   version "1.4-SNAPSHOT"
   sha256 "2ca5f13bc5efaf8515381e8cdf99b4d4017264a462a30366a873cb54cc4f4640"
-  revision 1
+  revision 2
 
   bottle :unneeded
 
-  depends_on :java => "1.8+"
+  depends_on "openjdk"
 
   def install
     rm_f Dir["bin/*.bat"]
     libexec.install "bin", "lib"
-    bin.install_symlink "#{libexec}/bin/frege-repl"
+    (bin/"frege-repl").write_env_script libexec/"bin/frege-repl", :JAVA_HOME => Formula["openjdk"].opt_prefix
   end
 
   test do