reduce git commands when get many commits info

[lunny]

[codecov-io]

Codecov Report

Merging #145 into master will increase coverage by 0.04%. The diff coverage is 68.42%.

@@            Coverage Diff             @@
##           master     #145      +/-   ##
==========================================
+ Coverage   37.28%   37.33%   +0.04%     
==========================================
  Files          28       28              
  Lines        1832     1843      +11     
==========================================
+ Hits          683      688       +5     
- Misses       1055     1059       +4     
- Partials       94       96       +2

Impacted Files	Coverage Δ
commit_info.go	62.6% <68.42%> (+0.93%)	:arrow_up:
repo_commit.go	23.77% <0%> (-1.51%)	:arrow_down:

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