code: function readYml(file, fn) {
  
    var m;
    var api = {};
    var resource = yaml.safeLoad(fs.readFileSync(file, 'utf8'));
    var paths = Object.keys(resource.paths);
    _.each(paths, function(path) {
      if (options.apiPrefix && path.indexOf(options.apiPrefix) === 0){
          path = path.replace(options.apiPrefix, "");
      }
      api.resourcePath = path;
      api.description = resource.description || "";
      descriptor.paths[path] = resource.paths[path];
  
      // append definitions
      if (descriptor.definitions && Object.keys(descriptor.definitions).length) {
        m = _.merge(descriptor.definitions, resource.definitions);
        descriptor.definitions = m;
      } else {
        descriptor.definitions = resource.definitions;
      }
    });
  
    fn();
  }
docs: Read from yml file