Add vote rate limit

src/middleware/voteRateLimit.js

@@ -0,0 +1,18 @@
+const config = require('../config.js');
+const getIP = require('../utils/getIP.js');
+const getHash = require('../utils/getHash.js');
+const rateLimit = require('express-rate-limit');
+
+module.exports = rateLimit({
+  windowMs: config.rateLimit.vote.windowMs,
+  max: config.rateLimit.vote.max,
+  message: config.rateLimit.vote.message,
+  headers: false,
+  keyGenerator: (req /*, res*/) => {
+    return getHash(req.ip, 1);
+  },
+  skip: (/*req, res*/) => {
+    // skip rate limit if running in test mode
+    return process.env.npm_lifecycle_script === 'node test.js';
+  }
+});