updated README
[refactor] move common funvtion to util.js

 Changes to be committed:
	modified:   1-infojson-from-videodb
	modified:   2-update-infojson
	modified:   3-create-dbjson
	modified:   4-migrate-videodb
	modified:   README.md
	modified:   migrate.sh
	modified:   package.json
	new file:   util.js