update patch to 2.7.5 and change to install stripped patch

packages/patch.rb

 require 'package'
 
 class Patch < Package
-  version '2.7'
-  source_url 'http://ftp.gnu.org/gnu/patch/patch-2.7.tar.gz'
-  source_sha1 '8886fe94a4cefaf42678ebeca25f4c012bd0f5dc'
+  version '2.7.5'
+  source_url 'https://ftp.gnu.org/gnu/patch/patch-2.7.5.tar.xz'
+  source_sha1 '8fd8f8f8ba640d871bce1bd33c7fd5e2ebe03a1e'
 
   def self.build
     system './configure --prefix=/usr/local'
@@ -11,6 +11,10 @@ class Patch < Package
   end
 
   def self.install
-    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install-strip"
+  end
+
+  def self.check
+    system "make", "check"
   end
 end