dhimmel/hetionet: Hetionet v1.0 in JSON, TSV, and Neo4j formats

Hetionet is a network of biomedical knowledge created by Project Rephetio, an open project to repurpose drugs. This release contains the Hetionet v1.0 network as described in https://doi.org/10.1101/087619. In this release, the Neo4j Docker which powers https://neo4j.het.io uses Neo4j 3.1.1. For more information on Project Rephetio, see https://thinklab.com/p/rephetio.