• adds support for Go 1.15 (Go 1.14 is also still supported)
• doesn't change support QUIC versions (i.e. is wire-compatible with v0.17.x release)
• adds a new logging / tracing interface, see logging.Tracer

Please note the release notes of the v0.17.3 release when upgrading a deployment that uses both quic-go clients and servers.