Run FHIR Server in Docker Container for Executing Integration Tests

[hhund]

Currently every Jetty integration test class generates a number of X509 certificates and starts/stops a Jetty server via JUnit code. The server only needs to be started once per build and the certificates could even be reused between builds unless mvn clean is called. We might want to think about using a docker container to start the Jetty server since we now depend on docker during a full build anyways.

Integrating the PostgreSQL template db mechanism for resetting the FHIR servers database might be tricky tho'.