Upgrade to Parquet 1.4.3

Note that Parqeut 1.4.3 handles default values differently
than in the past. If a record field is *not* part of the specified
projection, it will be set to the default value (if it exists)
instead of null.
Merge pull request #242 from massie/parquet-upgrade

Upgrade to Parquet 1.4.3