feat(@angular-devkit/build-angular): deprecate protractor builder

Author: alan-agius4

packages/angular_devkit/build_angular/README.md

@@ -13,7 +13,7 @@ This package contains [Architect builders](/packages/angular_devkit/architect/RE
 | karma        | Execute unit tests using [Karma](https://github.com/karma-runner/karma) test runner.                                                                                                                                                 |
 | ng-packagr   | Build and package an Angular library in [Angular Package Format (APF)](https://docs.google.com/document/d/1CZC2rcpxffTDfRDs6p1cfbmKNLA6x5O-NtkJglDaBVs/preview) format using [ng-packagr](https://github.com/ng-packagr/ng-packagr). |
 | server       | Build an Angular application targeting a [Node.js](https://nodejs.org) environment.                                                                                                                                                  |
-| protractor   | Run end-to-end tests using [Protractor](https://www.protractortest.org/) framework.                                                                                                                                                  |
+| protractor   | **Deprecated** - Run end-to-end tests using [Protractor](https://www.protractortest.org/) framework.                                                                                                                                 |
 | tslint       | **Deprecated** - Statically analyze [TypeScript](https://www.typescriptlang.org/) files using [TSLint](https://palantir.github.io/tslint/).                                                                                          |
 
 ## Disclaimer

packages/angular_devkit/build_angular/src/protractor/index.ts

@@ -73,11 +73,11 @@ async function updateWebdriver() {
 
   // run `webdriver-manager update --standalone false --gecko false --quiet`
   // if you change this, update the command comment in prev line
-  return webdriverUpdate.program.run(({
+  return webdriverUpdate.program.run({
     standalone: false,
     gecko: false,
     quiet: true,
-  } as unknown) as JSON);
+  } as unknown as JSON);
 }
 
 export { ProtractorBuilderOptions };
@@ -89,6 +89,10 @@ export async function execute(
   options: ProtractorBuilderOptions,
   context: BuilderContext,
 ): Promise<BuilderOutput> {
+  context.logger.warn(
+    'Protractor has been deprecated including its support in the Angular CLI. For additional information and alternatives, please see https://github.com/angular/protractor/issues/5502.',
+  );
+
   // ensure that only one of these options is used
   if (options.devServerTarget && options.baseUrl) {
     throw new Error(tags.stripIndents`