docs: function createTable(table, transaction) {
      return (transaction || db.knex).schema.hasTable(table)
          .then(function (exists) {
              if (exists) {
                  return;
              }
  
              return (transaction || db.knex).schema.createTable(table, function (t) {
                  var columnKeys = _.keys(schema[table]);
                  _.each(columnKeys, function (column) {
                      return addTableColumn(table, t, column);
                  });
              });
          });
  }