I'd like to add tests verifying that Beam is compatible with both Avro 1.8 and 1.9 similar to what has been done to Hadoop and Kafka.
Probably all Avro dependencies would have to be changed from compile to provided - won't it be problematic for users? They will be broken after the update unless they add Avro dependency. On the other hand they'll be able to choose which version do they prefer. At the moment Beam doesn't work with Avro 1.10 so users will be resticted to use either 1.8 or 1.9. Does changing Avro dependencies to provided sounds reasonable? Are there particular modules that should not be changed? Or is there a better approach?
