gem 'devise'
Run the bundle command to install it.

After you install Devise and add it to your Gemfile, you need to run the
generator:

rails generate devise:install
Removed all created session stuff. Added devise login and logout. Need
to redirect to user home.
Devise installed, app working as previous
Removing comments from files while transition to devise
Merge branch 'devise', remote-tracking branch 'origin'