Need to refresh security credentials after expiration

[drumadrian]

After running for several hours I discovered that log data was not being sent to Elasticsearch. This was the error from the python application started with an output logging file.

Error message:
DEBUG:elasticsearch:< {"message":"The security token included in the request is expired"}

Example invocation:

python3 myscript.py > output.txt

[jessci-aws]

Please review this...

This particular change allows passing refreshable credentials, which is a type of object that handles this particular problem directly and is supported by the dependency, requests-aws4auth.