What would you like to be added

Currently, the S3 endpoint is automatically created based on the bucket name/region and it is specific to AWS only.
DigitalOcean also supports S3 based API and allows existing tools to work with their offering called Spaces.

Current behavior:

bucket:
  name: test
  region: ams3

Generated URL: test.s3.ams3.amazonaws.com

Required behaviour:

Generated URL: test.ams3.digitaloceanspaces.com

Why is this needed

This will enable DigitalOcean users to utilize Darkroom over Spaces buckets.

Comments

Minimal change is required, S3's Go SDK supports specifying Endpoint in the configuration.