Add GroupController, tests and views
Make _session readonly
Refactor GroupControllerTests to use "IDisposable pattern"
Create DatabaseSeeder to inject sample data
Create route for non-group actions/controllers
Rename action parameter from id to slug
Remove redundant test method from HomeController
Rename Seed to Index on SeedController
Make GroupController survive duplicate slugs
Make group info page list members
List grupper i Home/Index
List groups in the "body" section instead of header
Fix connection string to point to correct database