Minor Description
In Avro 1.9 we started testing our builds also with Hadoop 3 as a provided dependency. Starting with 1.10 we can make Hadoop 3 the default version and also test Hadoop 2 for backwards compatibility.
Notice that hadoop is a provided dependency for Avro so downstream projects can choose a different version we (Avro) must only ensure that we test that Avro works for both Hadoop versions 2.x / 3.x