update attributes
add user model
authentication completed
add chapter 5
add chapter 5
add email password validate and test
Finsh user edit,update,index,and destroy action
Make a basic User model (including secure passwords)
add user test for factory_girl
Merge pull request #48 from chankaward/master

Finish Chapter 6
Merge pull request #47 from xiongbo/master

Finish Chapter 6
Merge pull request #45 from kaku87/master

完成第五章
some typo of migration #49
add sign-up
Finish user signup
Merge pull request #54 from xiongbo/sign-up

Finished Sign-up branch
Finish chapter 9
Merge branch 'master' of https://github.com/bay6/prepare
Merge pull request #55 from idanyzheng/master

这个PR迟到了
Start chapter 6, create User model, add email as index