Add route test generator

Give some guidance on testing routes.
Move railtie to its own file
Add minitest:all:quick testing task

This task runs all test files in a single task.
The advantage being that the tests run faster becasue the application doesn't reload.
The disadvantage being that tests are not reported in their groups.
Override the default test task [fixes #95]

Stop trying to play nicely with the default testing tasks and just stomp on it.
This will fix issues with integration tests running twice, once in each task.
Expose testing tasks to rake task list

Yes, this means that the task list just got even bigger.
But this might be justified because so many have questions about the tasks.
We can always quiet this up later.
Don't list the default tasks in desc because any changes (e.g in Rakefile) won't show.