NPM ecology network dataset

The dataset contains the dataset of the NPM ecology network. npm_openrank_top100.csv file contains the result of top 100 OpenRank repositories in npm ecology. npm_ecology.json file contains the original network of npm ecology open source repositories, use `CALL apoc.import.json('npm_ecology.json')` to import the network into Neo4j database. npm_ecology.dump file is generated by Neo4j dump command, use `bin/neo4j-admin load --from=npm_ecology.dump --database=npmecology --force` to load the data into Neo4j database. This will be much faster than loading from JSON file.