Fix OS detection

[demurgos]

No description provided.

[codecov-io]

Codecov Report

Merging #3 into master will not change coverage.
The diff coverage is 0%.

@@         Coverage Diff          @@
##           master    #3   +/-   ##
====================================
  Coverage      75%   75%           
====================================
  Files           1     1           
  Lines          20    20           
  Branches        4     4           
====================================
  Hits           15    15           
  Misses          3     3           
  Partials        2     2

Impacted Files	Coverage Δ
src/lib/index.ts	75% <0%> (ø)	⬆️

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