code: function filterFiles(gulp, options, taskFile){
  	var ext = path.extname(taskFile);
  	if(/\.(js|coffee)$/i.test(ext)){
  		createTask(gulp, options, taskFile);
  	}else if(/\.(json)$/i.test(ext)){
  		createMultitasks(gulp, require(taskFile));
  	}else if(/\.(ya?ml)$/i.test(ext)){
  		createMultitasks(gulp, readYAML(taskFile));
  	}
  }
docs: Filter files by extension.