Create frozen version of v1 Swagger spec and add equivalent OpenAPI spec

[jaeddy]

Based on #134, the idea would be to create a folder /openapi/v1/, which would include:

• workflow_execution_service.swagger.yaml
• workflow_execution_service.openapi.yaml

The swagger.yaml file would be the OpenAPI 2.0 version currently published under the 1.0.0 release. As we never provided a OpenAPI 3.0 version for that release, we'd ad the openapi.yaml (basically what's currently in develop as version 1.0.1 without the service-info integration).

With the bump to OpenAPI 3.0, we should also make sure that all models/components are correctly specified.

[jaeddy]

Also, because we probably shouldn't overwrite the current 1.0.0 tag/release (it's archived in Zenodo too...), I propose describing the versions for files under /openapi/v1/ (and similarly, in the future, keeping any x.0.y patch spec files under the respective folder). By extension, I'd like to rename the version with service-info as 1.1.0 and keep it under the base /openapi/ as our "latest" spec. I'll try to add some docs for this versioning approach as well.

[denis-yuen]

👍
Think we headed down this route with ga4gh/tool-registry-service-schemas#82