update gem file to make bootstrap works in heroku
add test method to test assistant test method
temp save
resolve conflict
make bootstrap work
complete draft of user model
add spec test for email downcase func
add spec test for email downcase func
finish practice of user modeling chapter
Merge branch 'modeling-users'
resolve conflict
update version of sass-rails
Revert "update version of sass-rails"

This reverts commit 4df60d340e60adaae70435685fedc679750f7c5f.
resolve railties version issue. Please rails in the end of Gemfile
complete signup
reslove conflict