etl manager should support / default to hive json serde

[isichei]

etl_manager/etl_manager/specs/json_specific.json

Line 6 in e4c3b75

"SerializationLibrary": "org.openx.data.jsonserde.JsonSerDe",

Probably should just create a second jsonl table support like we do with CSV

[isichei]

Also creating DDL for json writes the col description as 'from deserializer'