Add eslint and prettier to codebase and CircleCI

[sigmachirality]

• [x] Select eslint ruleset
• [x] Lint
• [x] Camelcase
• [x] QA all features to make sure lint didn't create bugs
• [x] Prettier also
• [x] CircleCI integration

Adds eslint and prettier, as well as adding a lint step to CircleCI.

If I requested a review from you, if you're platform, you only need to review the yaml, and if you're a frontend dev, you only need to review the js code/dev env setup.