Apply prettier formatting on codebase

[stevenmusumeche]

This PR upgrades prettier and adds a new npm run format command which runs it on the entire codebase. The rules are configured in .prettierrc, but I copied them from the eslint configuration to minimize the number of changes.

[coveralls]

Coverage increased (+0.02%) to 94.737% when pulling 7c3ff4a on stevenmusumeche:task/add-format-command into 8a2f7d7 on FormidableLabs:master.

[coveralls]

Coverage increased (+0.02%) to 94.737% when pulling 7c3ff4a on stevenmusumeche:task/add-format-command into 8a2f7d7 on FormidableLabs:master.

[coveralls]

Coverage increased (+0.02%) to 94.737% when pulling 7c3ff4a on stevenmusumeche:task/add-format-command into 8a2f7d7 on FormidableLabs:master.

[ryan-roemer]

I'm not reviewing as this is @kylecesmat 's game here, but in spectacle, we do our scripts this way:

// package.json
    "prettier": "prettier \"**/*.{js,json,css,md}\"",
    "prettier-fix": "npm run prettier -- --write",
    "prettier-check": "npm run prettier -- --list-different",

and run prettier-check in CI. It exits non-zero (failing the build) if prettier would change any files.

An alternative / additional way to do things is add the prettier plugins + rules to eslintrc.

All good approaches! Hope the tip helps :)

[blainekasten]

Closing in favor of #1012