text: 
  exports.up = function(knex) {
      return knex.schema.alterTable('users', tbl => {
          tbl.string('email');
          tbl.string('phone_number');
      });
  };
  
  exports.down = function(knex) {
      return knex.schema.table('users', tbl => {
          tbl.dropColumn('email');
          tbl.dropColumn('phone_number');
  })};
  