code: async function fetchAllDependents (name) {
    let pkg = await npm.getLatest(name)
    let deps = Object.keys(pkg.dependencies || {})
    if (!deps.length) return []
    let promises = []
    for (let dep of deps) {
      promises.push(fetchAllDependents(dep))
    }
    for (let subdeps of await Promise.all(promises)) {
      deps = deps.concat(subdeps)
    }
    return _.uniq(deps.sort())
  }
docs: traverses finding all dependents of a package