Broken with Ember 3.10.0

[Stefan Topfstedt]

Environment

• Ember Version: 3.10.0
• Ember CLI Version: 3.10.0
• Ember CP Validations Version: 4.0.0-beta.8

Steps to Reproduce

npx ember-cli-update --to=3.10.0
npm install
npm test

Fails with error message: EmberObject.create no longer supports defining computed properties. Define computed properties using extend() or reopen()

refs #635

[Pat O'Callaghan]

FYI this issue has started happening again with the Ember 3.13 beta but I have a fix here #653