Dynamic Columns (no config)

[aaronfischer]

What does this pull request do?

Upgrades to ember-cli 2.15.
Reorganize tabular to allow for automatically detecting columns based on the ember-data model. Also support defining custom column overrides via the template (no dependency on a controller).
Also uses new ember testing API (async/await)

What are the relevant issues?

#92 #88 #91 #90 #80 #107 #104 #93

Any background context you want to provide?

This version of ember-tabular only support ember-cli/ember 2.4 and up. All other version of ember should refer to the 0.1.0 tag.

Definition of Done:

Each should be selected to indicate consideration for applicability and/or completion.

• Does this PR fully satisfy the scope as outlined in the referenced issue(s)?
• Is there appropriate test coverage?
• Is static analysis resulting in a satisfactory score?
• If adding new dependencies, does pip requirements need to be updated?
• Has the change log been updated?

[aaronfischer]

Note: requires updating tests after upgrading to ember-power-select 2.X (Which also requires ember 2.9+).
This is due to ember-concurrency issues that require being on latest version to support ember-cli 3.6+.

When we get a chance, this is the PR to cut a new release that has a requirement of ember 2.9+.