Initial commit
Added beta server.js.
Modified server.js after the first meeting.

Moved the following commets to commit log.
- Set the function, which outputs the information of server URL, as callback of httpd.listen()
- Learned the difference between '==' and '==='
- Modified Content-Type to application/json from text/plain
- Modified README.md
Added test.js - test code for mocha
Modified server.js and test.js