Allow ember-auto-import v1 or v2

[mydea]

Since this addon is still supporting node 10, it isn't that easy to update to eai v2, as that requires node 12+.
So I first tried to set the dependency to "ember-auto-import": "^1.11.3 || ^2.2.4", but that threw an error on install time that the node engine was incompatible. Weirdly, that even happened when also setting a yarn resolution to ^1.11.3 locally 🤔

Now, I ended up allowing >= ^1.11.3 < 3, and adding a local resolution to ^1.11.3, which seemed to do the trick. As far as I can tell, this addon itself is not doing anything special with eai, so both v1 and v2 should generally work fine in a host app.

Once this addon drops support for node 10, we can remove the resolution (and do yarn add webpack --dev) and use eai 2 locally.

Closes #902

[mehulkar]

Since this addon is still supporting node 10

can we drop node 10 support? ember-cli doesn't support it either anymore

[SergeAstapov]

Agree with @mehulkar, we should just have a new major of this adding dropping support for Node 10 and adding e-a-i v2

[mydea]

I'm also fine with that, whatever is the preferred solution. Happy to update the PR, if I should do so? But would be great to get this landed one way or another :)

[CvX]

Anything blocking this PR? 😃

[locks]

Closed by #921.