Add Homebrew formula from 1.3.1

Homebrew/mas.rb

@@ -0,0 +1,29 @@
+class Mas < Formula
+  desc "Mac App Store command-line interface"
+  homepage "https://github.com/mas-cli/mas"
+  url "https://github.com/mas-cli/mas/archive/v1.3.1.tar.gz"
+  sha256 "9326058c9e572dd38df644313307805757d7ea6dfea8626e0f41c373ecbd46b5"
+  revision 1
+  head "https://github.com/mas-cli/mas.git"
+
+  bottle do
+    cellar :any_skip_relocation
+    sha256 "2d03fa8338e5a75ab8c93e6318607654306d17df3e747586a903d014bb102032" => :high_sierra
+    sha256 "9d50b4a359bbb100c341fff41a3690aa0c855b6651a1ac93ef4f6e974b9a7cd4" => :sierra
+    sha256 "05f5b0166c716896da57f0db781ae3f818dd2fbe561099f288b847c777687970" => :el_capitan
+  end
+
+  depends_on :xcode => ["8.0", :build]
+
+  def install
+    xcodebuild "-project", "mas-cli.xcodeproj",
+               "-scheme", "mas-cli",
+               "-configuration", "Release",
+               "SYMROOT=build"
+    bin.install "build/mas"
+  end
+
+  test do
+    assert_equal version.to_s, shell_output("#{bin}/mas version").chomp
+  end
+end