Proposal: remove transport constructors prior to release #305
Description
In #272, we made transports open structs, because it avoids the need for constructors and options, and because the transports always have an opportunity to set up state when they are Connected.
As part of that change, I deprecated but did not remove the old constructors and options types, primarily because I wanted to minimize churn, and allow the go:fix directives to work.
However, I think we should remove this deprecated API prior to the final release. Leaving this issue open as a reminder, and proposal for the breaking change.