用 karma start test/karma.conf.js 跑单元测试时候，karma报错如下：
No binary for PhantomJS browser on your platform. Please, set "PHANTOMJS_BIN"
解决方案：
(sudo ) npm install karma-phantomjs-launcher即可解决此问题
用 karma start test/karma.conf.js 跑单元测试时候，karma报错如下：
No binary for PhantomJS browser on your platform. Please, set "PHANTOMJS_BIN"
解决方案：
(sudo ) npm install karma-phantomjs-launcher即可解决此问题