Revert "Controllers that return `None` should be an HTTP 204."

This reverts commit fbcc2c27f7.

pecan/core.py

@@ -422,8 +422,6 @@ class PecanBase(object):
                 self.default_renderer,
                 self.template_path
             )
-        if namespace is None:
-            return None
         return renderer.render(template, namespace)
 
     def find_controller(self, state):

pecan/tests/test_base.py

@@ -2018,29 +2018,6 @@ class TestEngines(PecanTestCase):
         assert r.status_int == 200
         assert r.body == b_("Bill")
 
-    def test_template_with_no_namespace(self):
-        class RootController(object):
-            @expose('mako:mako.html')
-            def index(self):
-                return None
-
-        app = TestApp(Pecan(
-            RootController(),
-            template_path=self.template_path
-        ))
-        r = app.get('/')
-        self.assertEqual(r.status_int, 204)
-
-    def test_json_with_no_namespace(self):
-        class RootController(object):
-            @expose('json')
-            def index(self):
-                return None
-
-        app = TestApp(Pecan(RootController()))
-        r = app.get('/')
-        self.assertEqual(r.status_int, 204)
-
 
 class TestDeprecatedRouteMethod(PecanTestCase):