Part-way through implementing roles.
Merge branch 'master' of https://github.com/kitstone78/lamppost into roles
Add pry, pry-nab and other Gems for Development.
change to use for pry.
Create a user-type user and an Admin-type user.
Change the message user_id column to integer from string.
Add roles of User and Admin.  Use the CanCan gem to restrict the actions the roles can perform on the user and message through the views.  Restrict access to the admin views to logged-in users with the Admin role.
Change the Nav bar.  Change "Some Store" to Lamppost (with a link to the welcome page) and fix Messages and Users links.