Bump broccoli-autoprefixer to 7.0.0

[tansongyang]

This supersedes #40.

[tansongyang]

@kimroen Could you help me understand the build failure? Thanks!

[jrjohnson]

It looks like autoprefixer has dropped node v4 support at https://github.com/postcss/autoprefixer/releases/tag/9.0.0 so that should be removed from the tests.

It also looks like the API for broccoli-autoprefixer has changed in sindresorhus/broccoli-autoprefixer@5ff1490#diff-0730bb7c2e8f9ea2438b52e419dd86c9

to

const Autoprefixer = require('broccoli-autoprefixer');
tree = new Autoprefixer(tree, options);

So https://github.com/kimroen/ember-cli-autoprefixer/blob/master/index.js#L30 needs to be updated as well.

[tansongyang]

Hi @jrjohnson , thanks for following up. I believe I made the necessary changes, but it looks like something is still missing.

[jrjohnson]

@tansongyang I don't think these failures are part of your change. I put in #43 to update the addon to a more recent ember-cli structure and tests, once that is merged your changes will probably pass.

[tansongyang]

Thanks @jrjohnson! I'll keep an eye on it.

[acorncom]

@kimroen I'm interested in this change for a client project I'm working on. Would we be able to get a release here at some point?

[acorncom]

An update here. I ran @tansongyang's fork locally as part of an app I'm working on and got the following error message:

<path snipped>/assets/frontend.css.map:3:24: Missed semicolon
  1 | {
  2 | 	"version": 3,
> 3 | 	"file": "frontend.css",
    | 	                      ^
  4 | 	"sourceRoot": "<path snipped>/frontend/app/styles",
  5 | 	"sources": [

As I dug in, it looks like this PR may not actually be fully working. I ended up starting a brand new Ember app to test things out and as can be seen in this reproduction app, things aren't working there either. Interestingly, things fail regardless of use of .scss files or not (see my commit messages), so I think there's something else at play.

I also found that this command might help us zoom in a bit on seeing the steps that are running shortly before this occurs (but I'm not sure I'm in the right place):
DEBUG='fast-sourcemap-concat:*' ember s

[snewcomer]

#45 with 1.0.0-beta.0 released!