Adding support for nesting this addon

[mattxyzeth]

If this addon is used within another addon, an error is thrown about not being able to find the options hash on the app. Please see ember-cli/ember-cli#3718

[CAH-MaggieRoss]

Would really like to see this resolved--we're cleaning up our devDependencies and want to move this to regular dependencies so we can just include it once in our internal addon instead of having to include it in each app we use the addon in.

[kimroen]

Hi! Thanks very much for looking in to this.

I see the canary test is failing, but it doesn't seem related, so I'll merge this, figure out the tests, and then release it when everything is passing.

I was hoping there would be a more permanent solution for this issue, but it looks like this hotfix is the best option for now.

Thanks for being patient with me, I really appreciate your help.

[RobbieTheWagner]

Can you guys please elaborate how to use this in an addon? I assume I have to put options in index.js but it doesn't seem to prefix anything.