Update auth snippets.

Author: jmdobry

auth/auth.js

@@ -28,7 +28,7 @@ function authCloudImplicit () {
  // Instantiates a client. If you don't specify credentials when constructing
  // the client, the client library will look for credentials in the
  // environment.
- const storage = Storage();
+ const storage = new Storage();
 
  // Makes an authenticated API request.
  storage
@@ -55,7 +55,7 @@ function authCloudExplicit () {
  // Instantiates a client. Explicitly use service account credentials by
  // specifying the private key file. All clients in google-cloud-node have this
  // helper, see https://googlecloudplatform.github.io/google-cloud-node/#/docs/google-cloud/latest/guides/authentication
- const storage = Storage({
+ const storage = new Storage({
  keyFilename: '/path/to/keyfile.json'
  });