Updating autoprefixer to v7.1.x and postcss v6.0.x

[JulienBourgain]

Bug Report or Feature Request (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x] feature request

Versions.

@angular/cli@1.3.0-rc.5

Desired functionality.

In my project, i use css-grids and the default option in autoprefixer 6 is grid: true
In autoprefixer 7, it's grid: false

i think there is some other improvements

Mention any other details that might be useful.

[clydin]

This is waiting on cssnano 4.0 to be released to have a full postcss 6 pipeline.

[mgol]

Note that Autoprefixer 7 disables CSS Grid prefixes for IE by default so unless CLI passes the option explicitly (and unless there are more breaking changes there) the update to Autoprefixer 7 will be breaking and will require a major version bump of Angular CLI.

[kylecordes]

@mgol I wonder if would be sufficient to simply set grid: true, if that will be enough to make it possible to move up to v7, without having to simultaneously solve the problem of making autoprefixer configurable.

[mgol]

@kylecordes That might be worth it. From what I see in the changelog, this is the only breaking change aparts from dropping old Node versions that CLI doesn't support anyway.

It'd still be worth it to be able to configure PostCSS plugins but that's a separate issue.

[kylecordes]

@mgol I have a workaround in progress that does this and appears to work fine. Writeup coming soon.

[clydin]

@mgol @kylecordes PRs are welcome for the autoprefixer upgrade. As mentioned grid: true would need to be set to ensure compatibility.

[DaSchTour]

From what I see we are now at autoprefixer 8.2.5 and there is already a version 9. I think regarding this issue #11731 and #10076 it would be great to also introduce configuration for this in angular cli.

[alan-agius4]

These dependencies have been update