Doug fix go invocation

[Doug-AWS]

Issue #, if available:
I was getting the following error running 3-invoke.sh:

Invalid base64: "EVENTS.JSON"

Where EVENTS.JSON is the contents of events.json.

Description of changes:
Adding the following to the aws lambda command made it work:

--cli-binary-format raw-in-base64-out

Note that I'm still getting the following error on Windows:

{
    "StatusCode": 200,
    "FunctionError": "Unhandled",
    "ExecutedVersion": "$LATEST"
}
{"errorMessage":"fork/exec /var/task/main: permission denied","errorType":"PathError"}

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[Doug-AWS]

Nevermind. I found #180 fixes my issue. I'll file another issue for the Windows problem shortly.