add brew script for install on Mac

Author: liufengyun

dist/dotty.rb

@@ -0,0 +1,32 @@
+class Dotty < Formula
+  desc "Experimental Scala Compiler"
+  homepage "http://dotty.epfl.ch/"
+  url "http://dotty.epfl.ch/dotty/dotty-0.1.1-bin-SNAPSHOT.tar.gz"
+  sha256 "4e1bda148754543844d25290a87076e6bfb0b6b0275535f97c1871e0fc5c2c4c"
+  # mirror "https://downloads.typesafe.com/scala/2.12.2/scala-2.12.2.tgz"
+  # mirror "https://www.scala-lang.org/files/archive/scala-2.12.2.tgz"
+
+  bottle :unneeded
+
+  depends_on :java => "1.8+"
+
+  def install
+    rm_f Dir["bin/*.bat"]
+    prefix.install "bin", "lib"
+  end
+
+  test do
+    file = testpath/"Test.scala"
+    file.write <<-EOS.undent
+      object Test {
+        def main(args: Array[String]) {
+          println(s"${2 + 2}")
+        }
+      }
+    EOS
+
+    out = shell_output("#{bin}/dotr #{file}").strip
+
+    assert_equal "4", out
+  end
+end