refactor the whole damn thing

src/Util/generateUserID.js

@@ -0,0 +1,16 @@
+/* global crypto */
+
+export default function generateUserID () {
+  if (typeof crypto !== 'undefined' && crypto.getRandomValue != null) {
+    // browser
+    let arr = new Uint32Array(1)
+    crypto.getRandomValues(arr)
+    return arr[0]
+  } else if (typeof crypto !== 'undefined' && crypto.randomBytes != null) {
+    // node
+    let buf = crypto.randomBytes(4)
+    return new Uint32Array(buf.buffer)[0]
+  } else {
+    return Math.ceil(Math.random() * 0xFFFFFFFF)
+  }
+}