chore: Switch from gulp to gts, TypeScript 2.6 (googleapis#173)

* chore: adopt gts * chore: move from yarn to npm@5 (googleapis#172) * chore: pin the version of gts * chore: add comments for lint exceptions * BREAKING CHANGE: Use es module exports at top level The API has been optimized for ES Modules. The `GoogleAuth` and `DefaultTransporter` objects are now properties of the module. For example: ```js // es6/TypeScript import {GoogleAuth, DefaultTransporter} from 'google-auth-library'; // es5 const GoogleAuth = require('google-auth-library').GoogleAuth; const DefaultTransporter = require('google-auth-library').DefaultTransporter; ``` * chore: upgrade to gts@0.5.1

Author: JustinBeckwith

.clang-format

@@ -1,11 +1,11 @@
 node_modules/*
-/lib/
-/test/
+build/
 types/
 .idea
 .vscode
 docs/
 npm-debug.log
 coverage
 *.js.map
-yarn-error.log
+yarn-error.log
+**/*.js

.gitignore

@@ -4,10 +4,10 @@ language: node_js
 node_js:
  - "4"
  - "6"
- - "7"
+ - "8"
+ - "9"
 
 cache:
- yarn: true
  directories:
  - node_modules/
 

.travis.yml

@@ -60,7 +60,7 @@ the following snippet should work.
 
 ```js
 var google = require('googleapis');
-var GoogleAuth = require('google-auth-library');
+var GoogleAuth = require('google-auth-library').GoogleAuth;
 
 var authFactory = new GoogleAuth();
 var dns = google.dns('v1');