Working with ember 3.x

[aplex-dex]

Let's make master branch works correctly.

ember -v
ember-cli: 3.27.0 node: 12.22.6 os: darwin x64

• fix: build failed; downgrade to classic ember edition
  We must downgrade to last 3.x ember version to still use ember classic edition.
  https://deprecations.emberjs.com/v3.x/#toc_editions-classic

• fix: deprecation and errors array.new-array-wrapper
  We must fix new A deprecation, because it until: 3.9.0 and throw errors

• fix: tooltip undefined handleMouseLeave_
  just fixed

• fix: active tab attribute is not working /issues/134
  It's happend because this.get('composableChildren').length is 0, so child tabs aren't rendered at parent didInsertElement.

Thanks for contributing to this library! Please make sure that

• You've written some tests to go along with your code
• The automated testing passes successfully (without lint, we have 62 failed lint test now)
• You've updated the documentation (the dummy app for this addon) as appropriate (no required updates)
• You've provided an explanation as to what this feature/fix does, so that others can understand the intent while reviewing the code

So, now addon works with octane and classic ember editions and have passed tests.

Hi @mike-north Please let me know what do you think it's enough for merge/release new tag?