Using latest `pg` there is no `sqlScript` function on client

[cmcnicholas]

Describe the bug
The readme indicates the following:

    // Create postgrator instance
    const postgrator = new Postgrator({
      migrationPattern: __dirname + "/some/pattern/*",
      driver: "pg",
      database: "databasename",
      schemaTable: "schemaversion",
      execQuery: (query) => client.query(query),
      // the following client.sqlScript does not exist
      execSqlScript: (sqlScript) => client.sqlScript(sqlScript),
    });

To Reproduce
Just copy paste the readme

Expected behavior
Correct function being used or readme script altered to work.

Additional context
N/A