Improve code quality and write tests

node_modules/es6-promise/lib/es6-promise.js

@@ -0,0 +1,7 @@
+import Promise from './es6-promise/promise';
+import polyfill from './es6-promise/polyfill';
+
+// Strange compat..
+Promise.polyfill = polyfill;
+Promise.Promise = Promise;
+export default Promise;