Providing utility script to bulk update all episodes

This helps in part with #52.

server/update-all-episodes.js

@@ -0,0 +1,20 @@
+'use strict';
+
+require('dotenv').config();
+const request = require('request');
+const async = require('async');
+
+request(process.env.DATA_BUCKET+'episodes.json', (err, req, body) => {
+  let episodes = JSON.parse(body)
+    .map(episode => `http://localhost:3000/api/${process.env.API_HASH}/update/${episode.number}`);
+  console.log(`Updating ${episodes.length} episodes. This might take ${0.5*episodes.length} minutes.`);
+  async.mapSeries(episodes, function(url, callback) {
+    console.log('sending GET request to', url);
+    request(url, function(error, response, body) {
+      callback(error, body);
+    });
+  }, function(err, results) {
+    console.log(err);
+    console.log('Done updating all episodes.', results);
+  });
+});