Without an explicit name, it defaults to `mac_address_range_id`. Similar to the `subnet_id` situation mentioned in the commit message, it comes up with the following on migration:
```
sqlalchemy.exc.OperationalError: (OperationalError) (1280, "Incorrect index name 'mac_address_range_id'") 'ALTER TABLE quark_mac_addresses ADD UNIQUE (mac_address_range_id, address)' ()`
```
It needs to backtick the argument columns to create the index properly. I don't see how to configure alembic to do that.
```
mysql> alter table quark_ip_addresses add constraint subnet_id unique (subnet_id, address);
ERROR 1280 (42000): Incorrect index name 'subnet_id'
mysql> alter table quark_ip_addresses add unique subnet_id (`subnet_id`, `address`);
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0
```