code: function getSchema(connection) {
    const schema_sql = connection.schema_sql
      ? connection.schema_sql
      : SCHEMA_SQL_INFORMATION_SCHEMA;
    return runQuery(schema_sql, connection).then(queryResult =>
      formatSchemaQueryResults(queryResult)
    );
  }
docs: TODO - reviewed no change needed? datatypes need reviewing 
  Get schema for connection
  @param {*} connection