Not compatible with Ember 4+

Getting an error:
```console
Error: Could not find module `@ember/application/deprecations` imported from `@ember/test-helpers`
```
Because of https://deprecations.emberjs.com/v3.x/#toc_old-deprecate-method-paths, you need to upgrade the @ember/test-helpers to the latest version, which has dealt with the deprecation

I'm currently forcing the resolutions on that package in my project.

```javascript
// yarn
"resolutions": {
"ember-mocha/@ember/test-helpers": "^2.6.0"
},
// npm
"overrides": {
"ember-mocha": {
"@ember/test-helpers": "^2.6.0"
}
}
```