Add KNOEMA service provider

[eblondel]

KNOEMA is knowledge plateform that collates and disseminates public data (from both international and national data sources). When testing this service provider, they were 6066 dataflows available! Link is http://knoema.fr/api/1.0/sdmx (doc: http://knoema.fr/dev/opendata/sdmx)
This ticket is to add a test connector to this service provider.

[eblondel]

Hi @amattioc, maybe you are interested in plugging this datasource in your SDMX Java connector. It collates many datasets from several organizations. Cheers

[amattioc]

Hi @eblondel , thanks for the info. I'll have a look at this provider.

Best, Attilio