Allow Parquet as Response Format.

[aratikakadiya]

No description provided.

[pdowler]

For the ParquetWriterRoundtripTest: if you extended the AbstractTablesTest, you could write a complete lifecycle test pretty easily using utility methods in the base class. See CreateTableTest and LoadTableTest for examples.

• create table with all supported datatypes
• upload some rows
• query with VOTable output
• query with parquet output
• check for correctness (minimal like you have now)

[pdowler]

this mostly looks good - just one detail noted in test code.

I haven't reviewed the ParquetWriter test class - I think I'll wait until I can can pull the changes in and run it in my dev environment before looking at those details.