Don't require old time dependency

[kornelski]

A default feature in Chrono pulls in time v0.1, which is completely unnecessary for this crate, and on top of that currently it's marked by rustsec as vulnerable and unfixable.

[codecov]

Codecov Report

Merging #91 (13ed6a0) into master (5608390) will increase coverage by 0.21%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master       #91      +/-   ##
===========================================
+ Coverage   99.78%   100.00%   +0.21%     
===========================================
  Files          11        11              
  Lines         935       935              
===========================================
+ Hits          933       935       +2     
+ Misses          2         0       -2     

Impacted Files	Coverage Δ
src/feature/git.rs	100.00% <0.00%> (+1.41%)	⬆️

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