httpretty: working build for python3

pkgs/development/python-modules/httpretty/setup.py.patch

@@ -0,0 +1,11 @@
+--- setup.py    2016-04-18 10:44:27.915536022 -0500
++++ setup-new.py           2016-04-18 10:44:13.515537377 -0500
+@@ -75,7 +75,7 @@
+
+
+ local_file = lambda *f: \
+-    open(os.path.join(os.path.dirname(__file__), *f)).read()
++    open(os.path.join(os.path.dirname(__file__), *f), encoding="utf-8").read()
+
+
+ install_requires, dependency_links = \

pkgs/top-level/python-packages.nix

@@ -10420,7 +10420,6 @@ in modules // {
   httpretty = buildPythonPackage rec {
     name = "httpretty-${version}";
     version = "0.8.6";
-    disabled = isPy3k;
     doCheck = false;
 
     src = pkgs.fetchurl {
@@ -10442,6 +10441,9 @@ in modules // {
       --- 566 ----
       !                 'content-length': str(len(self.body))
       DIFF
+
+      # Explicit encoding flag is required with python3, unless locale is set.
+      patch -p0 -i ${../development/python-modules/httpretty/setup.py.patch}
     '';
 
     meta = {