Update ember-router-scroll

[san650]

This fixes a known issue in ember-router-scroll where you can get randomly failing tests.

See DockYard/ember-router-scroll#72

[san650]

For some reason, beta and canary are failing with this change. This is the error in travis-ci

https://travis-ci.org/ember-learn/ember-cli-addon-docs/builds/364861345

not ok 1 Chrome 65.0 - Global error: Uncaught TypeError: Cannot read property 'String' of undefined at http://localhost:7357/assets/vendor.js, line 123762
    ---
        Log: |
            { type: 'warn',
              text: '\'WARNING: Library "Ember" is already registered with Ember.\'\n' }
            { type: 'error',
              text: 'Uncaught TypeError: Cannot read property \'String\' of undefined at http://localhost:7357/assets/vendor.js, line 123762\n' }
    ...
not ok 2 Chrome 65.0 - Global error: Uncaught Error: Assertion Failed: The tests file was not loaded. Make sure your tests index.html includes "assets/tests.js". at http://localhost:7357/assets/vendor.js, line 25530
    ---
        Log: |
            { type: 'error',
              text: 'Uncaught Error: Assertion Failed: The tests file was not loaded. Make sure your tests index.html includes "assets/tests.js". at http://localhost:7357/assets/vendor.js, line 25530\n' }
    ...

Any idea what the issue might be?

[pzuraq]

This is an issue upstream with Ember, it should be fixed soon, the fix has already been merged I believe so we just have to wait for canary to update.

[san650]

Thanks @pzuraq for checking this!

[san650]

Tests green now 😃