update homebrew formula to 0.6.0

Author: yonaskolb

Formula/xcodegen.rb

@@ -1,8 +1,8 @@
 class Xcodegen < Formula
   desc "Tool that generates your Xcode project from a project spec"
   homepage "https://github.com/yonaskolb/XcodeGen"
-  url "https://github.com/yonaskolb/XcodeGen/archive/0.5.1.tar.gz"
-  sha256 "2be8807b02e0989e442a3022f0243fc524ec98ba0dc60a9b0db492f5c965513d"
+  url "https://github.com/yonaskolb/XcodeGen/archive/0.6.0.tar.gz"
+  sha256 "df6706abe40bab6fe911f71357bf30b0fcfa5c0e03c9edf252ed68e5f2fa0958"
   head "https://github.com/yonaskolb/XcodeGen.git"
 
   depends_on :xcode