add browser unit test

src/puppet-web/browser.spec.ts

+/**
+ * Wechaty - Wechat for Bot. Connecting ChatBots
+ *
+ * Licenst: ISC
+ * https://github.com/wechaty/wechaty
+ *
+ */
+import { test } from 'ava'
+
+import {
+  //   Config
+  // , log
+} from '../config'
+
+import {
+    Browser
+} from './browser'
+
+test.skip('quit()', async t => {
+  const browser = new Browser()
+  await browser.driver.init()
+
+  t.notThrows(async () => {
+    try {
+      await browser.quit()
+    } catch(e) {
+      throw e
+    }
+  }, 'should throw exception when call quit() on an un-init-ed browser')
+
+  t.throws(() => {
+    throw new Error('test')
+  }, Error, 'ok')
+  // browser.state.current('open', false)
+
+  // t.notThrows(() => {
+  //   browser.quit()
+  // }, 'should not throw exception when call quit() on an `inprocess` `open` state browser')
+
+  // t.throws(() => {
+  //   browser.quit()
+  // }, Error, 'should throw exception when call quit() twice on browser')
+
+})