Hi,

Firstly thanks for authoring this adapter. Really is great.

When I was deploying this earlier for my blog, I created an S3 Bucket in eu-west-2, which is the London Region. As per https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region, this S3 region only supports the latest Version 4 signature.

When configuring the ghost-storage-adapter-s3 plugin to point to this S3 endpoint, image uploads lead to the following error message: NAME: InternalServerError CODE: InvalidRequest MESSAGE: The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256.

Recreating the S3 bucket in the Ireland region, which supports Version 2 makes this error go away. I am unsure if this is a plugin specific issue or related to the AWS-SDK.