message: fix(service-worker): esm2015 points to wrong path
  The package.json esm2015 points to the wrong path.
  "esm15" should be "esm2015"
  Service Worker can't be compiled with use of Closure Compiler
  PR Close
diff: "description": "Angular - service worker tooling!",
  "main": "./bundles/service-worker.umd.js",
  "module": "./esm5/service-worker.js",
  - "es2015": "./esm15/service-worker.js",
  + "es2015": "./esm2015/service-worker.js",
  "typings": "./service-worker.d.ts",
  "author": "angular",
  "license": "MIT",
  