[keen-io] The date parser enrichment is not supported #321
Description
Migrated from #17 by @stringbeans
Keen has a pretty awesome date parser enrichment described here: https://keen.io/docs/api/#datetime-parser
However, when adding that configuration to the event body sent through Segment it seems to get stripped out by the time it reaches Keen. Can we add support for this by not overwriting the keen property in the body?