Algokey: Add -v flag to get the version

[algoganesh]

Summary

Algokey was missing a way to tell what version it's using. One should be able to run algokey -v and get the same output as goal -v.

Test Plan

algokey -v gives the same output as goal -v

[winder]

LGTM

[codecov]

Codecov Report

Merging #4004 (ad7df6e) into master (8bb8a4a) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4004      +/-   ##
==========================================
+ Coverage   49.80%   49.83%   +0.02%     
==========================================
  Files         409      409              
  Lines       69157    69157              
==========================================
+ Hits        34447    34462      +15     
+ Misses      30992    30981      -11     
+ Partials     3718     3714       -4     

Impacted Files	Coverage Δ
cmd/algoh/blockWatcher.go	77.77% <0.00%> (-3.18%)	⬇️
network/wsNetwork.go	62.99% <0.00%> (ø)
ledger/acctupdates.go	69.43% <0.00%> (+0.65%)	⬆️
ledger/tracker.go	76.62% <0.00%> (+1.29%)	⬆️
network/wsPeer.go	70.55% <0.00%> (+1.66%)	⬆️
ledger/roundlru.go	96.22% <0.00%> (+5.66%)	⬆️

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