Add support for newer dot region AWS S3 virtual host style paths

[picatz]

Following up on hashicorp/nomad#8454, the current tests don't include the newer virtual hosted style syntax, and doesn't seem to be supported. This is causing valid S3 paths to fail for Nomad's artifact stanza, and is a pain to debug / manually spot.

The S3 detector implementation should be adjusted to support the newer virtual host style paths using the dot region syntax.

Example

Newer virtual host style with S3 dot region endpoint structure:
https://legacy-player-resources.s3.eu-west-2.amazonaws.com/...
                                                               ☝️

Older virtual host style with S3 dash region endpoint structure:
https://legacy-player-resources.s3-eu-west-2.amazonaws.com/...
                                                               ☝️

The older dash-style that is supported is actually discouraged in the S3 documentation:

We recommend that you do not use this endpoint structure in your requests.

Phasing out S3 Path Style

To add to the complications, the other "path style" that is also supported will be soon phased out:

Support for the path-style model continues for buckets created on or before September 30, 2020. Buckets created after that date must be referenced using the virtual-hosted model.

[scalp42]

@picatz any timeline on this? I believe it's now broken with new buckets

[picatz]

@scalp42 sorry I don't have a timeline for this, yet!

Need to review/merge #283, cut a release, and get the updates in the required projects (like hashicorp/nomad#9050)

[picatz]

Fix released in v1.5.1

[scalp42]

awesome! thanks @picatz