Adapt API to download only desired files from dataverse according to user request.

[mauriciogtec]

[atrisovic]

If nn download:

• counties.geojson
• counties.graphml
• medisynth-nn-binary.csv
• medisynth-nn-binary.json
• medisynth-nn-continuous.csv
• medisynth-nn-continuous.json

If xgboost download:

• counties.geojson
• counties.graphml
• medisynth-xgboost-binary.csv
• medisynth-xgboost-binary.json
• medisynth-xgboost-continuous.csv

medisynth-xgboost-continuous.json

[atrisovic]

This one could also be closed now with #36. Or we can rename it to 'add text file to document available datasets'

[mauriciogtec]

Closed by #42