Allows Temporal Ingests from spark-etl to S3 - #2709

Hi @mattfullerton and sry for a long response! Can you squash your commits and sign it?
If you haven't signed ECA yet can you do it? After that just sign all your commits via git commit -s, more info can be found here: https://github.com/locationtech/geotrellis/blob/master/docs/CONTRIBUTING.rst#pull-requests
and you can reach us in our gitter channel to help you to get this contribution merged.

Also we don't plan to support this etl package anymore (we expect it to be dropped in 3.0) and plan to replace it with a pipeline that is not documented well at the moment, but you can find more info here: https://github.com/locationtech/geotrellis/blob/master/docs/CONTRIBUTING.rst#pull-requests

Any feedback is appreciated!

Hey, now it took me a while to reply; sorry about that.

I have never seen entry hurdles this big for making a (minor) PR to an OS project. Nevertheless, I have tried to squash the commits to one and sign it with a GPG id, same as the email address that has also signed the ECA. I hope I did it all correctly.

hey @mattfullerton thx for the update! it looks like you used git commit --amend -S (capital letter S) and not git commit --amend -s to add footers. Also I'm afraid i can't find that your email has the signed ECA, are you sure that it's a proper email?

I did the sign now with -s and signed the agreement (sorry, thought I only needed to sign up on the Foundation site)

thanks @mattfullerton, will merge it after CI would be happy!

Backported to 2.1 with d2e3666