Migrate from scss-lint to stylelint

[jglovier]

Scss-lint is giving us huge value in helping keep our CSS structured, consistent, and maintainable. The huge downside for our project, however, is that it requires Ruby, and as a Node based project that makes getting started for new contributors (especially Windows devs who don't have Ruby already installed on their machine) a significant barrier.

Scss-lint does have a Node ported version, but unfortunately it doesn't support all of the linters we need, including a few of the most valuable ones.

However, there is hope. And it's name is Stylelint. Stylelint appears to support everything that Scss-lint does, and has even more features. And best of all it is made for Node projects so it's way faster than Scss-lint (we've done some comparrison tests at GH and we are strongly considering moving from Scss-lint internally to Stylelint), and it would mean we no longer require Ruby for our app.

I'm strongly in favor of moving to Stylelint. Any objections?

cc @HospitalRun/core-maintainers

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Notes:

• Usage docs
• Stylelint repo
• Stylelint rules
• Scss-lint linters (will need to port from these to Stylelint rules)

---

TODO

• Install Stylelint
• Port scss-lint.yml rules to Stylelint config
• Integrate Stylelint with Travis testing
• Remove scss-lint
• Remove ember-cli-scss-lint

[jkleinsc]

@jglovier I'm fine with the change as long as it gets into the testing process with Travis. If we move to this we will also need to remove the ember-cli-scss-lint Ember addon.

[billybonks]

Probably the best way to do this would be to build ember-cli-style-lint addon

[jglovier]

also https://github.com/sasstools/sass-lint which is used by https://github.com/sir-dunxalot/ember-cli-sass-lint. pure node implementation.

@jkleinsc and I looked into switching to sass-lint at the hack week, but unfortunately it doesn't support a few key linting rules that we're getting with scss-lint.

[billybonks]

so this is ready for use https://www.npmjs.com/package/ember-cli-style-lint

[jglovier]

cc @jonrohan

[jonrohan]

This is a pretty new package https://github.com/kristerkari/stylelint-scss/ that has a lot of scss specific rules for stylelint. A++ would recommend

[jglovier]

Closed in #488.