add node modules to repo

node_modules/p-limit/index.js

@@ -0,0 +1,42 @@
+'use strict';
+const pTry = require('p-try');
+
+module.exports = concurrency => {
+	if (concurrency < 1) {
+		throw new TypeError('Expected `concurrency` to be a number from 1 and up');
+	}
+
+	const queue = [];
+	let activeCount = 0;
+
+	const next = () => {
+		activeCount--;
+
+		if (queue.length > 0) {
+			queue.shift()();
+		}
+	};
+
+	return fn => new Promise((resolve, reject) => {
+		const run = () => {
+			activeCount++;
+
+			pTry(() => fn()).then(
+				val => {
+					resolve(val);
+					next();
+				},
+				err => {
+					reject(err);
+					next();
+				}
+			);
+		};
+
+		if (activeCount < concurrency) {
+			run();
+		} else {
+			queue.push(run);
+		}
+	});
+};