Normalize whitespace in test arguments

We have a bunch of different styles of handling when function
definitions span multiple lines, which they almost always do with tests.

Here’s why an argument per line, single indent is best:
- cleaner diffs when you change the name of a method (one line change
  instead of multiple lines)
- works better on narrow screens, eg Github’s diff view, or with two
  terminals side by side on a laptop screen
- works with any editor’s indenting shortcuts, no need for an IDE

Also, trailing comma in the list of arguments is good because adding a
new argument to a method becomes a one line, not two line diff.

tests/app/main/views/test_forgot_password.py

@@ -20,10 +20,11 @@ def test_should_render_forgot_password(app_):
     'someuser@notonwhitelist.com'
 ])
 def test_should_redirect_to_password_reset_sent_for_valid_email(
-        app_,
-        fake_uuid,
-        email_address,
-        mocker):
+    app_,
+    fake_uuid,
+    email_address,
+    mocker,
+):
     with app_.test_request_context():
         sample_user = create_active_user(fake_uuid, email_address=email_address)
         mocker.patch('app.user_api_client.send_reset_password_url', return_value=None)
@@ -37,9 +38,10 @@ def test_should_redirect_to_password_reset_sent_for_valid_email(
 
 
 def test_should_redirect_to_password_reset_sent_for_missing_email(
-        app_,
-        api_user_active,
-        mocker):
+    app_,
+    api_user_active,
+    mocker,
+):
     with app_.test_request_context():
 
         mocker.patch('app.user_api_client.send_reset_password_url', side_effect=HTTPError(Response(status=404),