Add dev environment by gulp.js

Signed-off-by: Lee <jessy1092@gmail.com>
Update README.md

Signed-off-by: Lee <jessy1092@gmail.com>
update license in package.json

Signed-off-by: Lee <jessy1092@gmail.com>
Merge pull request #2 from jessy1092/gh-pages

Add dev environment by gulp.js