feat: add basic user feedback email mechanism

this definitely needs some more work.  using pyramid_mailer for
testing although not ready to declare that dependency.  for now this
is "broken" without it being installed.

tests/views/test_common.py

@@ -1,5 +1,9 @@
 # -*- coding: utf-8; -*-
 
+from unittest.mock import patch
+
+import colander
+
 from wuttaweb.views import common as mod
 from tests.util import WebTestCase
 
@@ -51,6 +55,68 @@ class TestCommonView(WebTestCase):
         context = view.home(session=self.session)
         self.assertEqual(context['index_title'], self.app.get_title())
 
+    def test_feedback_make_schema(self):
+        view = self.make_view()
+        schema = view.feedback_make_schema()
+        self.assertIsInstance(schema, colander.Schema)
+        self.assertIn('message', schema)
+
+    def test_feedback(self):
+        self.pyramid_config.add_route('users.view', '/users/{uuid}')
+        model = self.app.model
+        user = model.User(username='barney')
+        self.session.add(user)
+        self.session.commit()
+
+        view = self.make_view()
+        with patch.object(view, 'feedback_send') as feedback_send:
+
+            # basic send, no user
+            self.request.client_addr = '127.0.0.1'
+            self.request.method = 'POST'
+            self.request.POST = {
+                'referrer': '/foo',
+                'user_name': "Barney Rubble",
+                'message': "hello world",
+            }
+            context = view.feedback()
+            self.assertEqual(context, {'ok': True})
+            feedback_send.assert_called_once()
+
+            # reset
+            feedback_send.reset_mock()
+
+            # basic send, with user
+            self.request.user = user
+            self.request.POST['user_uuid'] = user.uuid
+            with patch.object(mod, 'Session', return_value=self.session):
+                context = view.feedback()
+            self.assertEqual(context, {'ok': True})
+            feedback_send.assert_called_once()
+
+            # reset
+            self.request.user = None
+            feedback_send.reset_mock()
+
+            # invalid form data
+            self.request.POST = {'message': 'hello world'}
+            context = view.feedback()
+            self.assertEqual(list(context), ['error'])
+            self.assertIn('Required', context['error'])
+            feedback_send.assert_not_called()
+
+            # error on send
+            self.request.POST = {
+                'referrer': '/foo',
+                'user_name': "Barney Rubble",
+                'message': "hello world",
+            }
+            feedback_send.side_effect = RuntimeError
+            context = view.feedback()
+            feedback_send.assert_called_once()
+            self.assertEqual(list(context), ['error'])
+            self.assertIn('RuntimeError', context['error'])
+
     def test_setup(self):
         self.pyramid_config.add_route('home', '/')
         self.pyramid_config.add_route('login', '/login')