Cannot add primary key with addColumn

[brookiel]

Some years ago this same issue came up in db-migrate/node-db-migrate#408. This was fixed by adding a check for a null options param:

    if (spec.primaryKey) {
      if (!options || options.emitPrimaryKey) {
        constraint.push('PRIMARY KEY');
      }
    }

A year later the call to createColumnDef from addColumn was changed to pass {} instead of null as options, which means this check always fails and the PRIMARY KEY constraint is never added. If you add an autoincrement field you are unable to set it as a primary key, resulting in the migration always failing with this error:

ER_WRONG_AUTO_KEY: Incorrect table definition; there can be only one auto column and it must be defined as a key

I have a PR to check for an empty object instead in the mysql adapter. This could be fixed upstream by changing the call to createColumnDef in db-migrate-base, but I'm hesitant to fix it there as other adapters don't seem to be having the issue.