Drop node 4 and Ember CLI < 2.13 (update to Ember 3.7 blueprint)

[loganrosen]

Updating this addon to Ember 3.5, leveraging ember-cli-update.

[jelhan]

This looks good to me beside adding package-lock.json instead of yarn.lock. It would close #86 and #85.

[loganrosen]

Since Ember 3.7 is available now, I've updated this PR accordingly. I also switched to Yarn per @jelhan's comment.

[rwjblue]

Seems good to me! When we release, we'll need to make sure to mark this as a breaking change (dropping Node 4, support for ember-cli < 2.13, etc).

[sandstrom]

@loganrosen Is there anything else you'd like to do with this PR, before we merge?

We'll make sure to add a changelog file where we can note that this is a breaking change. So that it'll be handled properly during the next version release.

[sandstrom]

friendly ping @loganrosen

[loganrosen]

@sandstrom Sorry for the delay! Just fixed a merge conflict against master (the Node version in .travis.yml was bumped to 8 in #84). This should be good to merge now, once Travis passes.

[sandstrom]

@loganrosen Great, thanks!

However, there seems to be a new error:

Could not require 'ember-cli-build.js': Cannot find module 'broccoli-caching-writer'

[loganrosen]

@sandstrom Fixed the Travis failure by setting useYarn to true in the ember-try configuration. This time I made sure it passed. 😄 Good to merge now.

[sandstrom]

@loganrosen Awesome, thanks!! 🙏🏻