release_2.0.0a2

New Features

• Support adding arbitrary env vars to test processes (#10715)
• Add a plugin hook for setup-py kwargs (#10721)

Bugfixes

• Fix the testutil wheel's imports not working due to
  namespace packages (#10725)
• Fix Pipenv not parsing requirement extras (#10722)
• Fix invalid shebang for BinaryPaths script (#10710)
• Fix retrieval of bytes from artifacts in StreamingWorkunitHandler
  (#10698)

Refactoring, Improvements, and Tooling

• Improve Pylint to use
  --python-setup-resolve-all-constraints (#10726)
• Reorganize pants/backend/python (#10724)
• Improve RuleGraph convergence time slightly (#10700)
• Snapshots of single files store normalized paths. (#10707)
• Add product type to the Rule trait to simplify unit testing.
  (#10720)

Testing

• Add RuleRunner.get_target() (#10714)
• Port more tests from TestBase to
  RuleRunner (#10704)

Documentation

• Formalize support for VCS-style requirements via PEP 440 (#10728)