Download and submit directly to GCS

[CarloLepelaars]

Context:

Numerblox supports Google Cloud Buckets (GCS) in downloaders and submitters with download_file_from_gcs, upload_file_to_gcs, download_directory_from_gcs and upload_directory_to_gcs. However, it always requires the user to have the Numerai data saved locally first.

Desired behavior:

• Download Numerai data directly to a GCS bucket with any downloader if directory_path is prefixed with gs://
• Upload predictions directly from a GCS bucket with any submitter if directory_path is prefixed with gs://

Possible bottlenecks:

• For NumeraiClassicDownloader this may require adding a feature to numerapi before we can get this working in NumerBlox.