Make version.py independent (open-mmlab#234)

* make version.py independent

* upper bound mmcv again

* tiny

* tiny

* use  and remove

* remove short_version in setup.py

* update setup.py

* update setup.py

* add unittest for parse_version_info

* remove unittest

Co-authored-by: dreamerlin <[email protected]>

Bump version to v0.6.0 (open-mmlab#159)

Update setup.py (open-mmlab#46)