Upgrade urfave cli to v2

[zix99]

No description provided.

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🔨 Latest commit	e49fb9f
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[codecov-commenter]

Codecov Report

Merging #77 (e49fb9f) into master (29bee6a) will increase coverage by 0.11%.
The diff coverage is 98.26%.

@@            Coverage Diff             @@
##           master      #77      +/-   ##
==========================================
+ Coverage   86.00%   86.11%   +0.11%     
==========================================
  Files          83       83              
  Lines        3372     3400      +28     
==========================================
+ Hits         2900     2928      +28     
  Misses        332      332              
  Partials      140      140              

Impacted Files	Coverage Δ
cmd/helpers/exitCodes.go	0.00% <0.00%> (ø)
cmd/analyze.go	97.22% <100.00%> (+0.12%)	⬆️
cmd/bargraph.go	100.00% <100.00%> (ø)
cmd/commands.go	100.00% <100.00%> (ø)
cmd/docs.go	100.00% <100.00%> (ø)
cmd/filter.go	85.45% <100.00%> (+0.54%)	⬆️
cmd/heatmap.go	96.72% <100.00%> (ø)
cmd/helpers/extractorBuilder.go	85.50% <100.00%> (+1.38%)	⬆️
cmd/histo.go	90.19% <100.00%> (+0.40%)	⬆️
cmd/tabulate.go	93.39% <100.00%> (+0.12%)	⬆️
... and 1 more

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