Add basic test that defaults are carried through

opentech/apply/categories/tests.py

-# from django.test import TestCase
-
-# Create your tests here.

opentech/apply/categories/tests/factories.py

+import factory
+
+from ..models import Category
+
+
+class CategoryFactory(factory.DjangoModelFactory):
+    class Meta:
+        model = Category
+
+    name = factory.Faker('word')
+    help_text = factory.Faker('sentence')

opentech/apply/categories/tests/test_blocks.py

+from django.test import TestCase
+
+from opentech.apply.categories.blocks import CategoryQuestionBlock
+
+from .factories import CategoryFactory
+
+
+class TestCategoryQuestionBlock(TestCase):
+    @classmethod
+    def setUp(self):
+        self.category = CategoryFactory()
+        self.block = CategoryQuestionBlock()
+
+    def test_field_and_help_default(self):
+        block = self.block.to_python({
+            'field_label': '',
+            'help_text': '',
+            'category': self.category.id,
+            'multi': False,
+        })
+
+        field = self.block.get_field(block)
+
+        self.assertEqual(self.category.name, field.label)
+        self.assertEqual(self.category.help_text, field.help_text)