Created helper to find current path: app/helpers/path_helper.rb

Updated layout: added nav bar with element displayed relative to the content and the user connected

Updated test to new index layout
spec/features/events_spec.rb

Changed views:
app/views/events/_index.html.erb
app/views/home/_nav.html.erb
app/views/home/index.html.erb
app/views/layouts/application.html.erb

Added route for logout: config/routes.rb

Updated session user tracking, changed id to user_id
app/helpers/users_helper.rb
app/controllers/session_controller.rb
app/controllers/users_controller.rb