- ECIInteraction.execute -- instruments the entry point for CICS
  calls via IBM's javax.resource.cci.Interaction implementation,
  creating "cics.execute" span and recording a few tags.
- JavaGatewayInstrumentation.flow -- records the peer.* tags on
  the "cics.execute" span created above, or if it doesn't exist,
  creates a new "gateway.flow" span.

The tests don't fully exercise the CICS client-side code, however
they exercise enough to ensure the instrumentation creates spans
and adds tags as expected.

This requires a few JAR files from IBM's CICS SDK for compliation
and testing that are not available in Maven Central. A tar.gz
artifact is downloaded from IBM's public CICS support archive
and the necessary JARs are extracted, following the same pattern
used for the JBoss Wildfly smoke tests.