added debuginfor,FactoryGirl,Gravatar
add microposts
finish chapter2
start chapter3
Improve the README
Serve static assets
added signup form
Add a StaticPages controller
simple TDD exercise
signup is ok
Finsh chapter7
add page(About Us) exercise
finish bootstrap layouts
Finish chapter 5
Merge pull request #38 from chankaward/master

Finish Chapter 5
Add a StaticPages controller
add home and help page
Finsh sign in
Merge pull request #39 from idanyzheng/master

迟到的pr
Update README.markdown