add connecting databse using mongoose.
add test scripts directory.
add express-resource npm to package.json.
set the app_name to 'librapi'.
add supertest npm.
change the script to run unittests.
add 'should' npm and add setting PORT number to the script of running
the test.
require express-resource.
write unittest of app.js.
add test_helper.js which configure default options for test.
write routing to user resouces.