Added class style to decorators that can be applied to view classes

        use_args.__init__(self, schema, **kwargs)

class doc(object):

class Doc(object):

    def __init__(self, **kwargs):

        self.kwargs = kwargs

        update_spec(f, self.kwargs)

        return f

doc = Doc

class tag(object):

class Tag(object):

    def __init__(self, tags):

        if isinstance(tags, str):

            self.tags = [tags]

        update_spec(f, {"tags": self.tags})

        return f

tag = Tag

class doc_response(object):

    def __init__(self, code, description=None, **kwargs):