Update app-lifecycle.spec
Update app-lifecycle.spec

Updated app-lifecycle.spec.js to include tests for the following:
- checking before:start, start, before:stop and stop on normal start/stop functionality
- checking that the above events are not called for apps that are trying to start and stop twice

RoundingWellOS/marionette.toolkit,TerrenceLJones/marionette.toolkit,paulfalgout/marionette.toolkit,paulfalgout/marionette.toolkit,TerrenceLJones/marionette.toolkit,paulfalgout/marionette.toolkit,RoundingWellOS/marionette.toolkit