rm fire_app_log.txt

I don't think we need the log file in SCM.
move mockup stuffs into the directory

To involve yeoman scaffolding.

Well, I do believe I break the workflow of working-on-mock-up.
I should fix it after discussion with ETBlue.
update gitignore to ignore some files we moved to mockup
use yeoman to build scaffolding

* yeoman
* generator-gulp-webapp
update project config

to make them fits don-republic more.