Dev: Connect to GCP storage

We don't claim to support GCP fully yet, but here's a snippet to test against it.

To do this yourself, create a GCP storage bucket and replace bucket with it.

Create a service user with HMAC credentials. Use those HMAC credentials as secret and key below.

from arcticdb import Arctic
secret = "<REDACTED>"
key = "<REDACTED>"
uri = "https://storage.googleapis.com"
bucket = "arcticdb-alex-seaton-bucket-1"
ac = Arctic(f"s3://{uri}:{bucket}?access={key}&secret={secret}")
ac.list_libraries()
ac.create_library("test")