v2.7.0 - Markdown, Sass rule updates, Atom integration

📝 Version 2.7.0 brings a new style configuration for Markdown documents. We use Markdown for documentation at Mobify and it should have a consistent style just like all of our code so let's automate that! This release includes a handy doc linting script (found in node_moduels/.bin/lint-md).

❗️ This release also updates the SASS linting rules to remove the variable-for-property rule.

⚛️ Finally it includes a short how-to document describing how to integrate eslint into Atom Text for on-the-fly lint warnings/errors.