Bump ember-maybe-in-element to supress build-time warning

[pzubar]

The current ember-maybe-in-element produces a warning during the build-time. The 2.1.0 version works fine on all the ember-source versions except the lts-3.16 (that throws an error described in that issue) so we cannot use it in order to provide the support for that ember version.

[tylerturdenpants]

Can we drop 3.16? Will @krasnoukhov be able to continue using it?

[pzubar]

I don't think we can drop 3.16 (it is still quite popular ) 😞
However, we can go another way and suggest ember-source <3.20 users using the package.json resolutions like that:

    resolutions: {
      'ember-maybe-in-element': '2.0.3'
    } 

P.S. Sadly, the "resolution" hack doesn't work with the ember try scenario for some reason.

[krasnoukhov]

I think we can merge this as is and also add a note to #774 about a better future solution