Prettier configs override prettierrc

[texastoland]

plugin:shopify/typescript-prettier and plugin:shopify/prettier pass Prettier config inline overriding any external config. It can be worked around but it took me a few hours to figure out why:

  prettier/prettier:
    - error
    - parser: typescript

[BPScott]

I'm fairly sure we can remove these overrides as we should trust the project's settings.

[texastoland]

I just fixed typescript-eslint-parser for TypeScript 3. I'll PR this and bump that at the same time.