Improve testing coverage after PR

# Problem

This [PR](https://github.com/code-corps/code-corps-ember/pull/1463#issuecomment-340201852) resulted in a substantial drop in test coverage (~1%) due to refactoring of imports. This seemingly shouldn't have an impact on testing coverage; however, the current thought is the imports from before this PR were picked up as covered by coveralls when in fact the actual logic was not covered. Here is an [example](https://coveralls.io/builds/13934987/source?filename=app%2Fmixins%2Fonboarding-controller.js).

Comece com o exemplo do Coveralls para app/mixins/onboarding-controller.js e compare a cobertura dele com as alterações em PR 1463, especialmente a refatoração dos imports. Identifique a lógica que é reportada como coberta sem testes e, em seguida, adicione cobertura para esse comportamento e verifique se o relatório geral não diminui mais após a refatoração.

Escrita pelo modelo de indexação a partir do texto da issue.