Add WebSphere integration tests

[felixbarny]

Seems like we can use https://hub.docker.com/r/ibmcom/websphere-traditional

[felixbarny]

I found out that the deployment directory is /work/app (see https://github.com/WASdev/ci.docker.websphere-traditional#building-an-application-image).

But I was unable to actually deploy and access an application. It seems to be a bit complicated. See also https://github.com/WASdev/ci.docker.websphere-traditional#adding-an-application-and-advanced-configuration-during-build-phase
Another challenge is that it uses https with self-signed certificates. That will make executing the endpoints a bit trickier.