Only cause mocha to fail on failed tests.

[jimschubert]

Emitting an error when the results from mocha are 0 causes gulp to incorrectly report an error:

[22:03:27] run mocha tests

  aurelia skeleton app
    ✓ should load the page and display the initial page title
    ✓ should display greeting (47ms)
    ✓ should automatically write down the fullname (1457ms)
    ✓ should show alert message when clicking submit button
    ✓ should navigate to flickr page (541ms)

  5 passing (21s)

[22:03:48] 'specs:e2e' errored after 22 s
[22:03:48] Error in plugin 'gulp-webdriver'
Message:
    0 tests failed.
[22:03:48] 'specs' errored after 29 s
[22:03:48] Error: [object Object]
    at formatError (/usr/local/lib/node_modules/gulp/bin/gulp.js:169:10)
    at Gulp.<anonymous> (/usr/local/lib/node_modules/gulp/bin/gulp.js:195:15)
    at Gulp.emit (events.js:129:20)
    at Gulp.Orchestrator._emitTaskDone (/Users/jim/temp/electron-aurelia-example/node_modules/gulp/node_modules/orchestrator/index.js:264:8)
    at /Users/jim/temp/electron-aurelia-example/node_modules/gulp/node_modules/orchestrator/index.js:275:23
    at finish (/Users/jim/temp/electron-aurelia-example/node_modules/gulp/node_modules/orchestrator/lib/runTask.js:21:8)
    at cb (/Users/jim/temp/electron-aurelia-example/node_modules/gulp/node_modules/orchestrator/lib/runTask.js:29:3)
    at finish (/Users/jim/temp/electron-aurelia-example/node_modules/run-sequence/index.js:53:5)
    at Gulp.onError (/Users/jim/temp/electron-aurelia-example/node_modules/run-sequence/index.js:60:4)
    at Gulp.emit (events.js:129:20)
[22:03:48] ended selenium session

Wrapping the broadcast of the event in a check prevents this.

[christian-bromann]

Thanks!