feat: add basic type

[hunjixin]

add basic type (repository/ref/object)

[codecov]

Codecov Report

Merging #15 (da30a94) into main (0c103b1) will increase coverage by 1.18%.
Report is 1 commits behind head on main.
The diff coverage is 81.57%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #15      +/-   ##
==========================================
+ Coverage   48.82%   50.01%   +1.18%     
==========================================
  Files          29       34       +5     
  Lines        4012     4163     +151     
==========================================
+ Hits         1959     2082     +123     
- Misses       1782     1801      +19     
- Partials      271      280       +9     

Files	Coverage Δ
models/user.go	72.72% <100.00%> (ø)
models/filemode/filemode.go	95.65% <95.65%> (ø)
models/object.go	81.25% <81.25%> (ø)
models/ref.go	72.72% <72.72%> (ø)
models/repository.go	72.72% <72.72%> (ø)
utils/hash/hash.go	81.81% <81.81%> (ø)
models/migrations/20210505110026_init_project.go	55.00% <45.45%> (-11.67%)	⬇️