chore: Set jest env as node to avoid jsdom overhead

[sudo-suhas]

Sets jest config in package.json. Reference docs - https://facebook.github.io/jest/docs/en/configuration.html#testenvironment-string

[codecov]

Codecov Report

Merging #189 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #189   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           5      5           
  Lines          67     67           
  Branches        8      8           
=====================================
  Hits           67     67

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[okonet]

Thanks! I didn't know that!

[sudo-suhas]

Me neither.. Got it from here - https://egghead.io/lessons/javascript-test-javascript-with-jest