Update the Go example to use Go modules: Move the example into a
directory containing a go.mod file, change the installation instructions
to use "go install".
Update the go_package option in addressbook.proto to an actual module path.
Update examples to use the google.golang.org/protobuf/proto module.
The example utilizes native bazel rules (proto_library, cc_proto_library,
java_proto_library, java_lite_proto_library) to show how easy it is to
build protobuf with bazel's native support. It also makes use of well
known types which was not possible until the latest bazel 0.5.4 release
and https://github.com/google/protobuf/pull/3594 .
This follows the other examples so that it can be used as a tutorial,
such as the ones at:
https://developers.google.com/protocol-buffers/docs/tutorials
Even though Go generally does not use Makefiles, I added targets for the
Go examples to be consistent with the other languages.
Edit:
Fix Travis run. Change to use $HOME instead of ~. Add protoc to path.
GOPATH entry cannot start with shell metacharacter '~': "~/gocode"
Edit(2):
Fix Go code style to address comments.