greg.tests: convert Consent model tests to pytest

Fixes: GREG-14

greg/tests/models/test_consent.py

+import pytest
+
+from greg.models import (
+    Person,
+    Consent,
+)
+
+
+@pytest.fixture
+def person() -> Person:
+    return Person.objects.create(
+        first_name="Test",
+        last_name="Tester",
+        date_of_birth="2000-01-27",
+        email="test@example.org",
+        mobile_phone="123456789",
+    )
+
+
+@pytest.mark.django_db
+def test_add_consent_to_person(person):
+    consent = Consent.objects.create(
+        type="it_guidelines",
+        consent_name_en="IT Guidelines",
+        consent_name_nb="IT Regelverk",
+        consent_description_en="IT Guidelines description",
+        consent_description_nb="IT Regelverk beskrivelse",
+        consent_link_en="https://example.org/it_guidelines",
+        user_allowed_to_change=False,
+    )
+    person.consents.add(consent, through_defaults={"consent_given_at": "2021-06-20"})

greg/tests/test_models.py

 from django.test import TestCase
 
 from greg.models import (
-    Person,
     OrganizationalUnit,
     Sponsor,
     SponsorOrganizationalUnit,
-    Consent,
 )
 
 
@@ -64,28 +62,3 @@ class SponsorModelTests(TestCase):
 
         sponsors_for_unit2 = Sponsor.objects.filter(units=unit2.id)
         self.assertEqual(0, len(sponsors_for_unit2))
-
-
-class ConsentModelTest(TestCase):
-    def test_add_consent_to_person(self):
-        person = Person.objects.create(
-            first_name="Test",
-            last_name="Tester",
-            date_of_birth="2000-01-27",
-            email="test@example.org",
-            mobile_phone="123456789",
-        )
-
-        consent = Consent.objects.create(
-            type="it_guidelines",
-            consent_name_en="IT Guidelines",
-            consent_name_nb="IT Regelverk",
-            consent_description_en="IT Guidelines description",
-            consent_description_nb="IT Regelverk beskrivelse",
-            consent_link_en="https://example.org/it_guidelines",
-            user_allowed_to_change=False,
-        )
-
-        person.consents.add(
-            consent, through_defaults={"consent_given_at": "2021-06-20"}
-        )