fix: support new swagger-codegen format for cloudsmith-api

[paddycarey]

This PR adjusts the CLI to support swagger-codegen's newer Configuration() style (without the global singleton).

Upstream change was made here swagger-api/swagger-codegen#9130

This change is required due to an upgrade in the swagger-codegen version we use to generate our API client libs over in cloudsmith-io/cloudsmith-api#27

[qlty-cloud-legacy]

Code Climate has analyzed commit 256e821 and detected 1 issue on this pull request.

Here's the issue category breakdown:

Category	Count
Complexity	1

The test coverage on the diff in this pull request is 0.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 0.9% (0.0% change).

View more on Code Climate.

[DavidS-cloud]

Should this also update https://github.com/cloudsmith-io/cloudsmith-cli/blob/master/setup.py#L55 to exclude incompatible API versions?

[paddycarey]

Should this also update https://github.com/cloudsmith-io/cloudsmith-cli/blob/master/setup.py#L55 to exclude incompatible API versions?

The CLI remains compatible with both old and new versions of the API bindings after this change, so no need to update here.