Added sign_in utilities method; added settings URL to header menu.
Added UserController > update method.
Finalized UserController > update method,
Added before_action :signed_in_user to :edit & :update actions of UserController to force a redirect to signin_url unless user is signed_in.
Added RSpec test for authorization as wrong user.
Added test for attempting to visit protected page.
Added redirect_back_or and store_location helper methods to sessions_helper.
Added Users index page.
Created lib/tasks/sample_data.rake for db:populate task to generate 100 test users.
Added FactoryGirl multiple user creation for pagination.  Added pagination to Users index.
Added admin flag to Users with appropriate tests.
Added User > Delete capabilities.