Update historical-requests for new S3 location

[buckett]

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• [x] Explain the motivation for making this change.
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Motivation (required)

Fixes the historical-requests subcommand to work with the new file location in S3.

Test Plan (required)

Run canvasDataCli historical-requests and check that it groups files by date range.

Next Steps

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• Make sure all tests pass, we will run this on jenkins but you can run it yourself with the build.sh script.

[buckett]

This should fix #40

[buckett]

Ok, but it's not that simple as the newer requests are of the format:

https://s3.amazonaws.com/<timestamp>/dw_split/<account>/requests/b%3D1/part-<uuid>.c001.txt.gz

so the code should cope with both options. This does mean you either get a range or a timestamp in the grouping.