v0.2

Fixed issues:
- #23:  Support BuildStream 2 
- #17:  Failed to parse ref format
- #16: Better version when commit is not a tag 
- #14: Potentially strange output if track-tags set to false 
- #7:  Produce overall report when MR generator completes 

Known issues:
- #25: Option to put all the updates in a single MR 
- #22: Better ignore handling 
- #15: An error of tracking on one element causes all other updates to fail 
- #10: Smarter push policy

Change log:
- !24:  Add argument for pointing at different GitLab 
- !23:  Add new CLI argument to point at different bst project root 
- !20:  Use different on_error policy on build and track
- !19:  Support bst2 by default, have parameter --bst1 
- !18:  Add parameter to make elements to submit MR's for random 
- !17:  Drop Python 3.6, add 3.9 and 3.10 
- !16:  Add matching for PEP-625 format files 
- !15:  Fix linter issues in CI 
- !13:  Disambiguate git tag updates with commit updates only 
- !12: Create summaries for auto_updater