code: function runAlias(aliasName, directories, options, argv) {
  	return new Promise((resolve, reject) => {
  		const tasks = getAllAliases(options)[aliasName];
  		if (!tasks) {
  			reject(new MrmUnknownAlias(`Alias “${aliasName}” not found.`));
  			return;
  		}
  
  		console.log(kleur.yellow(`Running alias ${aliasName}...`));
  
  		promiseSeries(tasks, name => {
  			return runTask(name, directories, options, argv);
  		})
  			.then(() => resolve())
  			.catch(reject);
  	});
  }
docs: Run an alias.
  
  @param {string} aliasName
  @param {string[]} directories
  @param {Object} options
  @param {Object} [argv]
  @returns {Promise}