node-challenge.js

var fs = require('fs')
var axios = require('axios')
var _ = require('lodash')
const bb = require('bluebird')
bb.promisifyAll(fs)

async function example () {
    const file = await fs.readFileAsync('./urls.txt','utf8')
    const urls = file.split('\n')
    const action = await bb.map(urls, async (url) => {
        const res = await axios.get(url)
        const content = JSON.stringify(res.body)
        const path = _.camelCase(url)
        const write = await fs.writeFile('./json/' + path, content)
        return {res, content, path, write}
    })
    return action
}

example().then(console.log)