[Enhancement] Update digit_version function

[ly015]

Update digit_version function according to open-mmlab/mmcv#1185 and open-mmlab/mmcv#1235

See also open-mmlab/mmpretrain#402

[codecov]

Codecov Report

Merging #865 (285e6bd) into master (775455d) will decrease coverage by 0.14%.
The diff coverage is 88.88%.

❗ Current head 285e6bd differs from pull request most recent head b68987f. Consider uploading reports for the commit b68987f to get more accurate results

@@            Coverage Diff             @@
##           master     #865      +/-   ##
==========================================
- Coverage   83.59%   83.44%   -0.15%     
==========================================
  Files         176      176              
  Lines       14145    14032     -113     
  Branches     2364     2369       +5     
==========================================
- Hits        11824    11709     -115     
+ Misses       1713     1712       -1     
- Partials      608      611       +3     

Flag	Coverage Δ
unittests	83.38% <88.88%> (-0.14%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
mmpose/__init__.py	90.32% <88.88%> (-9.68%)	⬇️
mmpose/datasets/dataset_wrappers.py	50.00% <0.00%> (-4.55%)	⬇️
mmpose/models/detectors/base.py	53.65% <0.00%> (-4.12%)	⬇️
mmpose/core/fp16/hooks.py	25.00% <0.00%> (-2.28%)	⬇️
mmpose/core/camera/camera_base.py	78.57% <0.00%> (-1.43%)	⬇️
mmpose/datasets/datasets/face/face_base_dataset.py	76.47% <0.00%> (-1.31%)	⬇️
mmpose/core/utils/regularizations.py	80.00% <0.00%> (-1.25%)	⬇️
mmpose/models/detectors/pose_lifter.py	68.26% <0.00%> (-1.11%)	⬇️
mmpose/datasets/pipelines/shared_transform.py	86.91% <0.00%> (-1.09%)	⬇️
mmpose/datasets/pipelines/loading.py	85.71% <0.00%> (-0.96%)	⬇️
... and 43 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 775455d...b68987f. Read the comment docs.

[innerlee]

Importing is good enough, and do not need to copy the implementation.

[ly015]

You mean importing from mmcv? I think the point of this PR is to avoid import this function from mmcv. Because digit_version from mmcv depends on mmcv version itself, like a circular dependency.

[innerlee]

Actually my thinking its the reverse. We will use the implementation of digit_version in mmcv, so that we will get automatic bug fixes.