Log Message:
Update go111 to 1.11.1.

go1.11.1 (released 2018/10/01) includes fixes to the compiler, documentation,
go command, runtime, and the crypto/x509, encoding/json, go/types, net,
net/http, and reflect packages. See the Go 1.11.1 milestone on our issue
tracker for details.

Also correct the PLIST and use ln -sf instead of ln -s.