Java 9 is commented out because there are some test failures that will be investigated later. Some tests had to be excluded from Java 7 because they don’t have a Java 7 compatible version.
Also updates all the contrib versions that we currently depend on to their 0.31.0 supporting versions.
Module: dd-trace -> dd-trace-ot Packages: Standardize on `datadog.trace` and `datadog.opentracing` as the package prefixes.
Tyler Benson