Update expect to chai.expect

- Updating expect to chai.expect.
- Removing workaround for vuejs/vue#9698
- Minor logging refactor

setup.js

@@ -1,18 +1,13 @@
+const expect = require('chai').expect;
+
 // setup JSDOM
 process.stdout.write('Setting up JSDOM...');
 require('jsdom-global')();
 
-// See https://github.com/vuejs/vue/issues/9698
-global.performance = window.performance;
-
 // See https://github.com/vuejs/vue-test-utils/issues/936#issuecomment-415386167
 window.Date = Date;
 
-if (window && window.document) {
-  process.stdout.write('OK.\r\n')
-} else {
-  process.stdout.write('Not OK.\r\n')
-}
+process.stdout.write(window && window.document ? 'OK.\r\n' : 'Not OK.\r\n');
 
-// make expect available globally
-global.expect = require('expect');
+// make chai.expect available globally
+global.expect = expect;