Migration express to koa
Add a keyword "Music"
Delete packages Q & express
Delete require modules (express & Q)
Add a package koa-router
Migrate to koajs: Delete express codes
Fix: typo url (add hyphen)
Migrate to koajs: Delete express.Router()
Merge pull request #2 from kubosho/feature-migration-express-to-koa

Migration: express to koajs