Custom Lambda Runtime

[scott-thomson239]

This is a draft PR of my current progress on issue #134 so people can have a look and give feedback/suggestions. I think the main parts that still need work are handling the errors for a possible failure during handler invocation and figuring out how to extract the headers and body from the Response gained from the GET request sent to the client into a LambdaRequest. I also need to test the runtime, which I have left for just now in case something needs changed.