Refactor/do not skip root

[otiai10]

Similar to @Antonboom 's original idea, except

• Change name of copyDispatcher to switchboard
• Do not use os.FileInfo
• Add some context in test cases

Thanks to @Antonboom

[codecov-commenter]

Codecov Report

Merging #25 into master will increase coverage by 1.92%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #25      +/-   ##
==========================================
+ Coverage   83.33%   85.26%   +1.92%     
==========================================
  Files           2        2              
  Lines          96       95       -1     
==========================================
+ Hits           80       81       +1     
+ Misses          8        7       -1     
+ Partials        8        7       -1     

Impacted Files	Coverage Δ
copy.go	83.90% <100.00%> (+2.08%)	⬆️

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[Antonboom]

Thank u!

@otiai10, could you make a new tag? :)

[otiai10]

v1.2.0 tagged