publishBuilder is not exported and annoying to use

[gabriel-vasile]

A publishBuilder can be used like this:

publishBuilder := pn.Publish()

publishBuilder.Channel("hello_world").Message(msg).Execute()

But looking in go docs for the package there is no entry for Channel(), Message(), or Execute().
This happens because publishBuilder is not exported but has exported methods.

golang/lint#210 explains why there are lint rules for situations like this.