Re-arranged tests, added new scenarios, and apparently caught some new
implementation errors.

Currently RED:
7 scenarios (3 failed, 4 passed)
47 steps (3 failed, 44 passed)

 On branch master
 Your branch is up-to-date with 'origin/master'.

 Changes to be committed:
	modified:   app/models/exzbike.rb
	modified:   app/views/exzbikes/_form.html.erb
	modified:   features/add_exzbike.feature
	modified:   features/step_definitions/exzbike_steps.rb