s3 file and directory loader with credentials passed in

[rysloan4]

Would be a nice feature to be able to pass aws_access_key_id and aws_secret_access_key into the S3FileLoader.init and S3DirectoryLoader.init.

[markeste]

Were you able to get the s3 directory loader to work? It looks like it crashes on IsADirectoryError: [Errno 21] Is a directory because it tries to load the directory in the prefix

[rysloan4]

Nope. Just iterating through the keys in a bucket and calling the file loader.