Read reads a set of files and returns lines as a PCollection<elem>
based on the internal avro schema of the file.
A type - reflect.TypeOf( YourType{} ) - with
JSON tags can be defined or if you wish to return the raw JSON string,
use - reflect.TypeOf("") -
Write writes a PCollection<string> to an AVRO file.
Write expects a JSON string with a matching AVRO schema.
the process will fail if the schema does not match the JSON
provided