Update lib.rs: Response vs Request in trace! log

[lmammino]

Issue #, if available:

Description of changes: If I understand the code correctly, the tracing line reports the content of the request, NOT the response.

If that's correct, I believe we should apply this change to make debugging a little bit easier.

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• I confirm that I've made a best effort attempt to update all relevant documentation.

[greenwoodcm]

the terminology is a little ambiguous. this is the event payload that the Lambda function was invoked with (so in that regard it's a request). but function code (or runtime code here) polls the Lambda runtime APIs for work and receives one payload at a time, as responses to that poll. so it's a request to the Lambda function, but a response from the runtime API. maybe we should change this line to say neither request nor response, but something like "event" or "payload".

[greenwoodcm]

looks like you need to reformat

[calavera]

I'll format it.

[lmammino]

Sorry, read a bit too late. Thanks for taking care of it, @calavera