code: function generateResourceListingForVersion(options) {
    var clone = JSON.parse(JSON.stringify(options.rootDocument));
    clone.info.version =  options.version;
    clone.basePath = options.basePath;
    clone.paths = clone.paths || {};
    clone.definitions = clone.definitions || {};
    mergeIn(clone.paths, buildPaths(options.controllers));
    mergeIn(clone.definitions, buildDefinitions(options.controllers));
  
    return clone;
  }
docs: build an specific spec based on options and filtered controllers