Add linting rules for formatting, and fix current linting errors

[stefanmajoor]

No description provided.

[codecov-commenter]

Codecov Report

Merging #144 (30afe52) into master (f1462a1) will not change coverage.
The diff coverage is 100.00%.

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Additional details and impacted files

@@           Coverage Diff           @@
##           master     #144   +/-   ##
=======================================
  Coverage   93.69%   93.69%           
=======================================
  Files           5        5           
  Lines         857      857           
  Branches      203      203           
=======================================
  Hits          803      803           
  Misses         44       44           
  Partials       10       10           

Files	Coverage Δ
src/Casts.js	73.21% <100.00%> (ø)

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