***update Gemfile.lock ***
***revert Gemfile.lock ***
***debug info ***
***add gravatar_for method ***
***update Gemfile version ***
***add user index and show pages ***
***update user controller ***
***add css for sidebar ***
***link signin path ***
***signin form ***
***show user info with gravatar***
***add private method for user controller***
add css for form
show flash message
add css info for errors
render shared page for error message
use strong params to protect attr
use SSL for production