* ci: stop building darwin/386 binaries
Go 1.15 drops support for 32-bit binaries on Darwin https://golang.org/doc/go1.15#darwin
* tls: ConnectionState::NegotiatedProtocolIsMutual is deprecated in Go 1.15, this value is always true
* correct error messages that changed slightly
* Completely regenerate some TLS test data
Co-authored-by: R.B. Boyer <rb@hashicorp.com>
Ronald