Use IC shared lint/prettier config

[nathanmarks]

I'm preparing a PR to add typings to the repo and would like to be able to have them linted (and prettified!). Rather than adding the TypeScript eslint plugins and support to the existing config, @dcocchia suggested that converting Snacks to use our shared configs instead of it's own lint config would be a good move (our shared configs already have TS support and prettier integration).

Most of the changes here are from prettier/eslint auto fixes but there are some manual changes.

I'll try to point out the manual changes in comments (apart from the children prop additions).

note:

• codecov is failing because of the change in # of lines from prettier formatting -- there were no actual changes in functionality or tests
• codeclimate is failing because I fixed a typo in some propTypes and there's repeated code

[codecov[bot]]

Codecov Report

Merging #316 into master will decrease coverage by 0.98%. The diff coverage is 75.35%.

@@            Coverage Diff             @@
##           master     #316      +/-   ##
==========================================
- Coverage   81.13%   80.14%   -0.99%     
==========================================
  Files          59       59              
  Lines        1060     1088      +28     
  Branches      223      215       -8     
==========================================
+ Hits          860      872      +12     
- Misses        147      164      +17     
+ Partials       53       52       -1

[dcocchia]

Thanks for point out each manual change 🙏🙏 Makes this much nicer to go through :)

[mmarcuccio]

@nathanmarks tested locally, and things are working great. 🚢