DefaultApiVersionReporter and websockets

[israellot]

DefaultApiVersionReporter tries to add headers to the response for websocket requests.
This results in invalid operation since the headers were already sent along the HTTP 101 status.

[commonsensesoftware]

I'm assuming this is ASP.NET Core and the same symptoms as #273.

It appears the platform differences require Core to write the headers before the action is processed and Web API should write after the action is processed.

I should have the fix out within the next couple of days. Thanks.