Add CLI parameters: --add-network-file, --add-variant-file...

[jtarraga]

The admin commad line for buiding CSV files should support the following parameters:

• --add-network-file , a JSON file containing a network according to the BioNetDB network data model.
• --add-variant-file , to a file containing variants in JSON format, one variant per line.

For instance:
$ bionetdb-admin.sh build -i ~/download -o ~/build --add-network-file ~/test/clinical_analysis.network.json