postman 学习网址
postman使用详解:
http://gold.xitu.io/entry/57597a62a341310061337885
https://www.getpostman.com/docs/writing_tests
http://bayescafe.com/tools/use-postman-to-test-api-automatically.html
https://zh.wikipedia.org/wiki/%E8%A1%8C%E4%B8%BA%E9%A9%B1%E5%8A%A8%E5%BC%80%E5%8F%91