Close some of the IE compatibility issues (#7)

* es5 compatible

* upticked

index.js

@@ -49,7 +49,7 @@ if (shouldPolyfillEventTarget) {
     ) {
       if (arguments.length < 2) {
         throw new TypeError(
-          `TypeError: Failed to execute 'addEventListener' on 'EventTarget': 2 arguments required, but only ${arguments.length} present.`
+          "TypeError: Failed to execute 'addEventListener' on 'EventTarget': 2 arguments required, but only " + arguments.length + " present."
         );
       }
       const __listeners = this.__listeners;
@@ -71,7 +71,7 @@ if (shouldPolyfillEventTarget) {
     ) {
       if (arguments.length < 2) {
         throw new TypeError(
-          `TypeError: Failed to execute 'addEventListener' on 'EventTarget': 2 arguments required, but only ${arguments.length} present.`
+          "TypeError: Failed to execute 'addEventListener' on 'EventTarget': 2 arguments required, but only " + arguments.length + " present."
         );
       }
       const __listeners = this.__listeners;
@@ -87,14 +87,17 @@ if (shouldPolyfillEventTarget) {
     EventTarget.prototype.dispatchEvent = function (event) {
       if (!(event instanceof Event)) {
         throw new TypeError(
-          `Failed to execute 'dispatchEvent' on 'EventTarget': parameter 1 is not of type 'Event'.`
+          "Failed to execute 'dispatchEvent' on 'EventTarget': parameter 1 is not of type 'Event'."
         );
       }
       const type = event.type;
       const __listeners = this.__listeners;
       const listenersForType = __listeners.get(type);
       if (listenersForType) {
-        for (const [listener, options] of listenersForType.entries()) {
+        for (var listnerEntry of listenersForType.entries()) {
+          const listener = listnerEntry[0];
+          const options = listnerEntry[1];
+
           try {
             if (typeof listener === "function") {
               // Listener functions must be executed with the EventTarget as the `this` context.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "event-target-polyfill",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "description": "An EventTarget Polyfill",
   "main": "index.js",
   "exports": {