create SSOLoginPolicy, which allows factors to be applied when user comes from SSO login

implement SESSIION_IS_SSO_LOGIN for OAuth Client and core MFA

passbook/core/migrations/0024_ssologinpolicy.py

@@ -0,0 +1,25 @@
+# Generated by Django 2.2 on 2019-04-29 21:14
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('passbook_core', '0023_remove_user_applications'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='SSOLoginPolicy',
+            fields=[
+                ('policy_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='passbook_core.Policy')),
+            ],
+            options={
+                'verbose_name': 'SSO Login Policy',
+                'verbose_name_plural': 'SSO Login Policies',
+            },
+            bases=('passbook_core.policy',),
+        ),
+    ]