Prepare for OpenTracing 0.31.0 release #188
Description
OpenTracing 0.31 (currently RC2) is a breaking API change: opentracing/opentracing-java#189
Even though TChannel code does not use any of the breaking methods directly, I found crossdock tests in Jaeger client are breaking because tchannel classes are trying to load non-existing io.opentracing.BaseSpan.