Add webauthn as an auth type.

Both in our models and as a migration to add it to auth_types
table.

Make sure that if we downgrade, we first clean up the data.

migrations/versions/0356_add_webautn_auth_type.py

@@ -0,0 +1,40 @@
+"""
+
+Revision ID: 0356_add_webautn_auth_type
+Revises: 0355_add_webauthn_table
+Create Date: 2021-05-13 12:42:45.190269
+
+"""
+from alembic import op
+
+revision = '0356_add_webautn_auth_type'
+down_revision = '0355_add_webauthn_table'
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.execute("INSERT INTO auth_type VALUES ('webauthn_auth')")
+
+    op.drop_constraint('ck_users_mobile_or_email_auth', 'users', type_=None, schema=None)
+    op.create_check_constraint(
+        'ck_user_has_mobile_or_other_auth',
+        'users',
+        "auth_type in ('email_auth', 'webauthn_auth') or mobile_number is not null"
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.execute("UPDATE users SET auth_type = 'sms_auth' WHERE auth_type = 'webauthn_auth'")
+    op.execute("UPDATE invited_users SET auth_type = 'sms_auth' WHERE auth_type = 'webauthn_auth'")
+
+    op.drop_constraint('ck_user_has_mobile_or_other_auth', 'users', type_=None, schema=None)
+    op.create_check_constraint(
+        'ck_users_mobile_or_email_auth',
+        'users',
+        "auth_type = 'email_auth' or mobile_number is not null"
+    )
+
+    op.execute("DELETE FROM auth_type WHERE name = 'webauthn_auth'")
+    # ### end Alembic commands ###