Add digital ocean and amd dev backend

[Bihan]

Steps

1. Login to both clouds https://cloud.digitalocean.com/login and https://amd.digitalocean.com/login

2. To configure backends add

  - type: amddevcloud
    project_name: TestProject
    creds:
      type: api_key
      api_key: <api_key_amd_dev_cloud>
  - type: digitalocean
    project_name: TestProjectNvidia
    creds:
      type: api_key
      api_key: <api_key_digitalocean>

Note: Will be updating the PR with project_name configuration. Creation of Droplet (VM) was not documented in api reference, but recently found that "project_id" field works.

[jvstme]

@Bihan, thanks for the PR. The division into two backends looks good to me 👍 Please also see my comments about some implementation details

[jvstme]

@Bihan, thanks for the update. I think we are almost ready to merge. The remaining things are:

• Bump gpuhunt to 0.1.8 in pyproject.toml
• Address my non-nitpicking comments on the latest update
• Optionally address my nitpicking comments

If you decide to follow my code suggestions and there will be no details to discuss, feel free to merge without repeating the review. Thank you!