Add lint command to makefile

[solar05]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1142 (ad26cc2) into master (a13918a) will increase coverage by 0.19%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1142      +/-   ##
==========================================
+ Coverage   73.58%   73.77%   +0.19%     
==========================================
  Files         130      130              
  Lines        2612     2612              
==========================================
+ Hits         1922     1927       +5     
+ Misses        690      685       -5     

Impacted Files	Coverage Δ
services/app/lib/codebattle/game/engine.ex	90.84% <0.00%> (+0.70%)	⬆️
services/app/lib/codebattle/bot/server.ex	86.36% <0.00%> (+6.06%)	⬆️

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