Renderer uses form field's label and help, not attribute name
Turns out label and help_text are not always there
Move and rename LabelModelSerializer for further reuse
Change BasicModel.verbose_name

Isn't it nicer to test for a text which is different from
what the previous broken behavior was? Now we can really
tell it works!
Update FieldLabelTest to use new BasicModel.verbose_name
Two test cases for html rendering of API with labelized model