Fixes #206 fix ember-polyfills.deprecate-merge deprecation

[habdelra]

Fixes the deprecation:

DEPRECATION: Use of `merge` has been deprecated. Please use `assign` instead. [deprecation id: ember-polyfills.deprecate-merge] See https://emberjs.com/deprecations/v3.x/#toc_ember-polyfills-deprecate-merge for more details.

[marcoow]

We're still supporting Ember < 2.0 actually (see https://github.com/simplabs/ember-cookies/blob/master/config/ember-try.js) which means we'd have to add https://github.com/shipshapecode/ember-assign-polyfill to not make this a breaking change.

[Turbo87]

@habdelra in what situation did you hit that deprecation? we are defaulting to using Object.assign() or the non-deprecated Ember.assign() so I'm wondering what caused that deprecation message for you 🤔

[habdelra]

It's actually neither Object.assign nor Ember.assign polyfill. It is the Ember.merge polyfill that is deprecated in 3.7. and it looks like just importing it was triggering the deprecation message.

[habdelra]

Specifically it fixes this issue: #206

[marcoow]

Looking at the source, the deprecation should only be triggered once merge is actually invoked. I also couldn't see it when running the demo app or the tests 🤔

[marcoow]

I believe this was fixed by #204 already actually - I'll release a new version including that.

[habdelra]

Could you also rev ember-simple-auth with the new ember-cookies to?