update coding style

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
remove drone.io test status

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
remove Gruntfile.js, rename coffeescript to coffee and add npm start command

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
update grunt

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>