Upgrade swagger from 2.0 to swagger/openapi 3.0

The leap from swagger 1.6.2 to swagger 3 (OpenAPI 4) could be quite huge. The longer we wait, the more challenging the eventual upgrade becomes. OpenAPI 4.0’s release date isn’t guaranteed (correct me if i am wrong) where by even after release, it’s usually wise to wait for the ecosystem to stabilize in order to see community adoption and tool support before migrating.

The idea is to really first having it