fix: download results from us-2-west bucket

[guss84]

closes #78

The cause of the issue is that we use rasterio to download tiff files from the S3 bucket, with a pre-signed url. The pre-signed url differed between us-west-2 and eu-central-1, where us-west-2 url was using signature version 2 which resulted an a 403 error when raterio.gdal was trying to fetch the image.

[zcernigoj]

Tested running process graph with Landsat (on us-west) on production and locally running this fix and it looks like the fix works.