Event Grid trigger always returns HTTP 202

[glaserbeamer]

Summary:
When an Event Grid trigger function throws an exception, I would expect an HTTP 500 to be returned to Event Grid; instead, this returns an HTTP 202, so Event Grid believes that processing was successful, and it never replays the event.

Repro steps:

1. Add new "Event Grid trigger" function (C#).
2. Change body of function to "throw new Exception();"
3. Save and run.

Sample log output (using default/sample event):
2018-04-20T02:21:43.875 [Info] Function started (Id=)
2018-04-20T02:21:44.125 [Error] Exception while executing function: Functions.EventGridTriggerCSharp1. mscorlib: Exception has been thrown by the target of an invocation. f-EventGridTriggerCSharp1__1818170464: Exception of type 'System.Exception' was thrown.
2018-04-20T02:21:44.187 [Error] Function completed (Failure, Id=, Duration=313ms)

HTTP return code:
202 Accepted

[paulbatum]

This issue was moved to Azure/azure-functions-eventgrid-extension#35