added omniauth, better_errors, and binding_of_caller gems; added omniauth initializer.rb
corrected wrong gem name to better_errors and added initializer for better_errors' vagrant fix
created user model, users and sessions controller; added helper method for current_user in appcontroller; added users' new view
added routes for root (users#new), provider callback, and signout for github
set environment variables in a YAML call in omniauth init, modified users' new view, updated .gitignore; closes #2
added signout link once logged in onto users#new view
modifed :notice to :alert, added flash[:alert] for Signed-In and Signed-Out
Fixed whitespace tabs to spaces; added newline at end of file
added comment about alternative ENV variable usage
updated .gitignore to ignore Gemfile.lock* and app/assets/stylesheets/users.css.scss* files