Add columns for requested and allowed broadcast areas for a service

We want to restrict where broadcast services can broadcast to.

Hence we are creating columns on service_broadcast_settings table
to store the lists of allowed_broadcast_areas and
requested_allowed_broadcast_areas.

migrations/versions/0351_allowed_broadcast_areas.py

@@ -0,0 +1,31 @@
+"""
+
+Revision ID: 0351_allowed_broadcast_areas
+Revises: 0350_update_rates
+Create Date: 2021-04-09 12:51:17.158043
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+revision = '0351_allowed_broadcast_areas'
+down_revision = '0350_update_rates'
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('service_broadcast_settings', sa.Column(
+        'allowed_broadcast_areas', postgresql.JSONB(none_as_null=True, astext_type=sa.Text()), nullable=True)
+    )
+    op.add_column('service_broadcast_settings', sa.Column(
+        'requested_allowed_broadcast_areas', postgresql.JSONB(none_as_null=True, astext_type=sa.Text()), nullable=True)
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('service_broadcast_settings', 'requested_allowed_broadcast_areas')
+    op.drop_column('service_broadcast_settings', 'allowed_broadcast_areas')
+    # ### end Alembic commands ###