Add radio buttons for choosing the API key type

Best-guess wording for what the labels and question should be.

Adds a macro for rendering radio buttons from a WTForms field.

tests/app/main/test_create_api_key_form.py

@@ -1,3 +1,5 @@
+import pytest
+
 from werkzeug.datastructures import MultiDict
 
 from app.main.forms import CreateKeyForm
@@ -11,4 +13,20 @@ def test_return_validation_error_when_key_name_exists(app_):
         form = CreateKeyForm(_get_names(),
                              formdata=MultiDict([('key_name', 'Some key')]))
         form.validate()
-        assert {'key_name': ['A key with this name already exists']} == form.errors
+        assert form.errors['key_name'] == ['A key with this name already exists']
+
+
+@pytest.mark.parametrize(
+    'key_type, expected_error', [
+        ('', 'This field is required.'),
+        ('invalid', 'Not a valid choice')
+    ]
+)
+def test_return_validation_error_when_key_type_not_chosen(app_, key_type, expected_error):
+
+    with app_.test_request_context():
+        form = CreateKeyForm(
+            [],
+            formdata=MultiDict([('key_name', 'Some key'), ('key_type', key_type)]))
+        form.validate()
+        assert form.errors['key_type'] == [expected_error]