Add new SMS rates for 1 May 2022 onwards

This change can be merged before the new rates go live, because they
won't be used until the start date.

migrations/versions/0369_update_sms_rates.py

@@ -0,0 +1,24 @@
+"""
+
+Revision ID: 0369_update_sms_rates
+Revises: 0368_move_orgs_to_nhs_branding
+Create Date: 2022-04-26 09:39:45.260951
+
+"""
+import uuid
+
+from alembic import op
+
+revision = '0369_update_sms_rates'
+down_revision = '0368_move_orgs_to_nhs_branding'
+
+
+def upgrade():
+    op.execute(
+        "INSERT INTO rates(id, valid_from, rate, notification_type) "
+        f"VALUES('{uuid.uuid4()}', '2022-04-30 23:00:00', 0.0172, 'sms')"
+    )
+
+
+def downgrade():
+    pass