updates mlflow to used proxied artifact storage

[laurencejackson]

Updates mlflow to use proxied artifact storage. This streamlines artifact access and reduces complexity of server for users.

Updates mlflow to 2.1.1

Resolves #110

[github-actions[bot]]

Coverage Report

File	Stmts	Miss	Cover	Missing
mlops
Experiment.py	151	30	80%	44–49, 69, 76–77, 94, 96, 101, 170–184, 202, 204–205, 253–254, 262–265, 269–270, 277–278
ProjectFile.py	22	1	95%	38
_version.py	1	1	0%	1
cli.py	19	19	0%	1–52
mlops/data/tools
tools.py	111	91	18%	22–29, 32–34, 37–69, 72–119, 132–204
mlops/data/transforms
LoadImageXNATd.py	53	41	23%	23–28, 50–109
TOTAL	384	183	52%

Tests	Skipped	Failures	Errors	Time
14	2 :zzz:	0 :x:	0 :fire:	34.737s :stopwatch: