fix: remove node globals

[hugomrdias]

This PRs cleans ups old stuff and removes node globals

ref:
ipfs/js-ipfs#2924

[codecov]

Codecov Report

Merging #175 into master will increase coverage by 0.07%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #175      +/-   ##
==========================================
+ Coverage   96.13%   96.20%   +0.07%     
==========================================
  Files          15       15              
  Lines         207      211       +4     
==========================================
+ Hits          199      203       +4     
  Misses          8        8              

Impacted Files	Coverage Δ
src/dag-link/dagLink.js	91.66% <100.00%> (+0.36%)	⬆️
src/dag-node/dagNode.js	91.66% <100.00%> (+0.17%)	⬆️
src/dag-node/rmLink.js	90.00% <100.00%> (+1.11%)	⬆️
src/dag-node/sortLinks.js	100.00% <100.00%> (ø)
src/util.js	100.00% <100.00%> (ø)

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[vmx]

Thanks for the note, let me know when it is ready to merge.