PyArrow and Parquet DELTA_BINARY_PACKED

[Feras Salim]

Hi, I was wondering if I'm missing something or currently the
`DELTA_BINARY_PACKED` is only available for reading when it comes to
parquet files, I can't find a way for the writer to encode timestamp data
with `DELTA_BINARY_PACKED`, furthermore I seem to get about 10% increase in
final file size when I change from ver 1 to ver 2 without changing anything
else about the schema or data.