Generated client does not honor @http trait

[jabalsad]

Hello,

We define our HTTP endpoints using the @http trait on operations, e.g.:

@http(uri: "/create_account", method: "POST")
operation CreateAccount {
...

Taken from https://awslabs.github.io/smithy/1.0/spec/core/http-traits.html

But these paths are nowhere to be found in the generated go client.

[jasdel]

This issue is similar to #354. Since the smithy-go codegen does not include any protocols implementation it cannot understand the @http trait. Lets use #354 to track this general concept and feature request.