Update Jenkinsfile to deploy agent when needed

[kevinearls]

Currently the agent option of collector/agent does not work as there is no agent. (In the https://github.com/Hawkular-QE/jaeger-instrumentation-performance-tests the agent gets deployed by the fabric8-maven-plugin as part of deploying the test application.) . So we need to deploy the agent as a sidecar here.

[kevinearls]

According to Pavol: "You will probably have to package your test as a real app, then you can use the same approach si in instrumentation tests." Maybe we can take the part of the test that creates the spans, package that as a wildfly-swarm app with a single rest endpoint, and have the test hit that endpoint and wait for it to complete.

Pavol also said "It does not have to be web app, it can be a plain main class a job in k8s terminology." In either case we have to kick off an application somewhere else, wait for it to finish, and then go count traces.