* js rewriting: default to moden js-proxy based rewriting by default, use legacy rewriting only if browsers are older than minimum, as suggested in #707
* user-agent detection: use ua_parser for user-agent detection instead of obsolete werkzeug.useragent, which also did not support browsers >=100
* tests: additional tests for rewriting with various user-agents, defaulting to new-style rewriting for unknown browsers
* dockerfile: Update Dockerfile to use py3.8
* tests: skip s3 tests dependent on commoncrawl data (for now, need better s3 tests).
* bump to 2.6.6, update CHANGES
403167fbe0