Update backbone.marionette to 1.8.0

Sources:
https://github.com/marionettejs/backbone.marionette/archive/v1.8.0.zip
https://github.com/marionettejs/backbone.marionette/archive/v1.7.4.zip
https://github.com/marionettejs/backbone.marionette/archive/v1.7.3.zip
and
https://github.com/marionettejs/backbone.marionette/archive/v1.7.2.zip

Should fix https://github.com/cdnjs/cdnjs/issues/2976