Disply debug info if env is development
User#show
Add factory_girl_rails gem
First Factory Girl
users show page
Set password hash cost minimum for test performance
Gravatar
Sidebar
User#create

Fix sign up page style for bootstrap3.
Flash message
Fix bootstrap style
Optional Gravatar size
Test of sign up error page
Test of a user page after sign up
Improve using by content_tag
Merge branch 'sign-up'