Functional testing: Add tests to cover current functionality

We did a lot of development before we got the kuryr tempest plugin. Now that we have it we should add the following test cases to make sure that we cover most of the codebase:

- Spawn a pod and a second one that successfully pings the first
- Spawn an http server pod with readiness and liveness probes to make sure kubelet -> pod probes work
- spawn a pod and a VM and test communication
- spawn a service with three pods and another pod that consumes the service verifying that all the endpoints answer
- Same but resizing the service and checking that no connections are lost
- Port pools
    - Create a Pod, then create N - 1 pods where N is the batch creation size. Ensure that only one neutron port creation operation happened.
    - Create N Pod and delete M pods where M < N. Check that N-M ports where returned to the pool