v0.2.0

Added uniqueness validation
Fixed pylint warnings

v0.2.1

Fixed json assert errors in unit test
Added support for Raw field

v0.2.2

Fixed json serialization error of datetime objects for invalid rows in dataframe.

v0.2.3

Updated marshmallow-oneofschema dependency to version ~=3.0
Updated schema unit test to use Raw field

v0.2.4

Fixed schema processing for marshmallow Nested field with many=True option.