Add license check script for incompatible licenses in pip dependencies (#16753)
NVDA is licensed with GPL2 which is incompatible with certain licenses like Apache.
Currently there are 2 python dependencies bundled with NVDA with incompatible licenses:
fast-diff-match-patch - see Reconsider fast_diff_match_path license violation workaround #16633
requests
Description of user facing changes
Developers can now check licenses with runlicensecheck.bat
AppVeyor checks that new dependencies with incompatible licenses aren't introduced
Description of development approach
Using the licensecheck pip dependency, check licenses
Similar to lint checks, run these checks on appveyor builds