v0.39.0

What's Changed

• chore(docs): oss headers, coc, and contributors by @wolf31o2 in #252
• chore(deps): bump golang.org/x/crypto from 0.8.0 to 0.9.0 by @dependabot in #261
• feat: make protocol identifiers public by @agaffney in #265
• fix: check for shutdown to avoid hang on close by @agaffney in #263
• test: framework for mocking Ouroboros connections by @agaffney in #266
• fix: protect stop/start/close functions from being called again by @agaffney in #269
• fix: close connection on muxer stop by @agaffney in #270
• test: Ouroboros double close test by @agaffney in #272
• test: basic handshake tests by @agaffney in #271

Full Changelog: v0.38.4...v0.39.0