Update diffutils from 3.5-1 to 3.6

packages/diffutils.rb

@@ -3,11 +3,11 @@ require 'package'
 class Diffutils < Package
   description 'GNU Diffutils is a package of several programs related to finding differences between files.'
   homepage 'http://www.gnu.org/software/diffutils/'
-  version '3.5-1'
-  source_url 'ftp://ftp.gnu.org/gnu/diffutils/diffutils-3.5.tar.xz'
-  source_sha256 'dad398ccd5b9faca6b0ab219a036453f62a602a56203ac659b43e889bec35533'
+  version '3.6'
+  source_url 'https://ftp.gnu.org/gnu/diffutils/diffutils-3.6.tar.xz'
+  source_sha256 'd621e8bdd4b573918c8145f7ae61817d1be9deb4c8d2328a65cea8e11d783bd6'
 
-  depends_on "libsigsegv"
+  depends_on 'libsigsegv'
 
   def self.build
     system "./configure --prefix=/usr/local"