I'm using `ember-code-snippet` with the library `ember-cli-addon-docs` and I can't use the component `code-snippet`. It fails in [this line of code-snippet component](https://github.com/ef4/ember-code-snippet/blob/master/addon/components/code-snippet.js#L5) with the Error `TypeError: this.callback.apply is not a function`. The Error is thrown from [loader.js](https://github.com/ember-cli/loader.js/blob/master/lib/loader/loader.js#L136). I'm using the latest versions of Ember (3.10), ember-cli-addon-docs (0.6.12), ember-code-snippet (2.4.0) and loader.js (4.7.0). Does anybody has any clue about what's happening? Is somebody having the same problem? Thanks!