Feature/#9 postcss config

[michealengland]

Closes #9

Description

• Setup CSS Nano to apply on production builds and minify styles.
• Add PostCSS Safe Parser to prevent incorrect CSS from being transcoded into production builds.
• Setup Media Query Packer to extract and organize media queries throughout styles.
• Add Node Sass in place of Precss. Note: While precss is favorable for build speed and features it does not support traditional Sass syntax at this time for certain features.
• Add sass-loader to webpack config and install node-sass package along with sass-loader.
• Uninstall precss releated packages.
• Update postcss.config and remove out precss related requirements.

How to Test

Reviewers can test this feature by checking out this branch locally and using npm run dev and npm run build to inspect files. Optionally you can also use the test branch provided below.

Test Branch

I setup test examples in style.scss on example/#9-postcss-test.

Features to Test

1. Sass functionality works correctly
2. Using npm run dev build files work properly
3. Using npm run build production files build as expected
4. Verify that media queries group correctly
5. Verify that incorrectly written styles do not make it's way into built files