Merge pull request #2 from easeway/user-login

add model spec skeleton
add libnotify for linux
Merge pull request #4 from whywhy36/notification

add libnotify for linux
Add system design document
Merge pull request #5 from xiebing/master

Add system design document
use devise for user login logic
Merge branch 'master' of github.com:vmw-tmpst/heroapp-LetsHire into user-login