* Add Date support to the parquet reader
Add support for the Date logical type. Currently this is not supported. Since the parquet
date is number of days since epoch gets interpreted as seconds since epoch, it will fails
on indexing the data because it will not map to the appriopriate bucket.
* Cleaned up code and tests
Got rid of unused json files in the examples, cleaned up the tests by
using try-with-resources. Now get the filenames from the json file
instead of hard coding them and integrated general improvements from
the feedback provided by leventov.
* Got rid of the caching
Remove the caching of the logical type of the time dimension column
and cleaned up the code a bit.
Fokko Driesprong