lepton 1.2.1 (new formula)

lepton 1.2 (new formula)

https://blogs.dropbox.com/tech/2016/07/lepton-image-compression-saving-22-losslessly-from-images-at-15mbs/

Closes #3012.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Formula/lepton.rb

@@ -0,0 +1,21 @@
+class Lepton < Formula
+  desc "Tool and file format for losslessly compressing JPEGs"
+  homepage "https://github.com/dropbox/lepton"
+  url "https://github.com/dropbox/lepton/archive/1.2.1.tar.gz"
+  sha256 "c4612dbbc88527be2e27fddf53aadf1bfc117e744db67e373ef8940449cdec97"
+  head "https://github.com/dropbox/lepton.git"
+
+  depends_on "cmake" => :build
+
+  def install
+    system "cmake", ".", *std_cmake_args
+    system "make", "install"
+  end
+
+  test do
+    cp test_fixtures("test.jpg"), "test.jpg"
+    system "#{bin}/lepton", "test.jpg", "compressed.lep"
+    system "#{bin}/lepton", "compressed.lep", "test_restored.jpg"
+    cmp "test.jpg", "test_restored.jpg"
+  end
+end