Error: Unknown provider: $$rAFProvider when running karma test

I Keep getting this error when trying test a simple angular service. The code is based off of this excellent post which I followed exactly.

[http://sebastien.saunier.me/blog/2014/02/04/angular--rails-with-no-fuss.html][1]

Every thing seems to suggest that somehow the test dependencies don't match the version of angular but I'm using the v 1.3.14 of both angular and angular-mocks.

Thanks

Error: Unknown provider: $$rAFProvider
            at /Users/herbyraynaud/code/myapp/node_modules/karma-ng-scenario/lib/angular-scenario.js:12207
            at getService (/Users/herbyraynaud/code/myapp/node_modules/karma-ng-scenario/lib/angular-scenario.js:12333)
            at decorator (/Users/herbyraynaud/code/myapp/node_modules/karma-ng-scenario/lib/angular-scenario.js:12261)
            at /Users/herbyraynaud/code/myapp/vendor/bundle/gems/rails-assets-angular-mocks-1.3.14/app/assets/javascripts/angular-mocks/angular-mocks.js:1837
            at invoke (/Users/herbyraynaud/code/myapp/node_modules/karma-ng-scenario/lib/angular-scenario.js:12363)
            at /Users/herbyraynaud/code/myapp/node_modules/karma-ng-scenario/lib/angular-scenario.js:12287
        TypeError: 'null' is not an object (evaluating 'httpBackend.when')
            at /Users/herbyraynaud/code/myapp/spec/javascripts/angular/services/rubygems_spec.js:19
        TypeError: 'null' is not an object (evaluating 'httpBackend.verifyNoOutstandingExpectation')


  [1]: http://sebastien.saunier.me/blog/2014/02/04/angular--rails-with-no-fuss.html