Pom file testsuite/pom.xml defines profile forward.compatibility.  Associated
comments state,
  "Forward compatibility: use EAP 7.0.0.GA and newer Client from CP stream
   (e.g. client from RESTEasy delivered by EAP 7.0.2"
and " Uncomment module below when EAP/Widlfly with Resteasy 3.1 is released".

This is referencing very old code.  RESTEasy is now at version 4.x and EAP 7.3.x.

I am planning to remove this profile unless someone provides a compelling reason
to keep it.