message: refactor(docs-infra): refactors `extractDecoratedClasses`
  This commit removes the dependency on the `lodash` module and refactors
  the `extractDecoratedClasses` method.
  PR Close
diff: -var _ = require('lodash');
  -
  module.exports = function extractDecoratedClassesProcessor(EXPORT_DOC_TYPES) {
  // Add the "directive" docType into those that can be exported from a module
  @@ -10,12 +8,9 @@ module.exports = function extractDecoratedClassesProcessor(EXPORT_DOC_TYPES) {
  $runBefore: ['docs-processed'],
  decoratorTypes: ['Directive', 'Component', 'Pipe', 'NgModule'],
  $process: function(docs) {
  - var decoratorTypes = this.decoratorTypes;
  -
  - _.forEach(docs, function(doc) {
  -
  - _.forEach(doc.decorators, function(decorator) {
  -
  + const decoratorTypes = this.decoratorTypes;
  + docs.forEach(doc => {
  + (doc.decorators || []).forEach(decorator => {
  if (decoratorTypes.indexOf(decorator.name) !== -1) {
  doc.docType = decorator.name.toLowerCase();
  // Directives do not always have an argument (i.e. abstract directives).
  