v0.19.0

What's Changed

• fix: decompressive transcoding improvements by @coryan in #322
• test: add httpbin tests by @coryan in #323
• test: relax startup matcher by @coryan in #326
• fix: replace default_object_acl in grpc update bucket op by @cojenco in #327
• feat: replace httpbin by @coryan in #325
• ci: stop testing with Python 3.6 by @coryan in #329

Full Changelog: v0.18.0...v0.19.0