Fix IE11 (#56)

* Correct commonjs transpilation for IE11
* Improve rollup ordering and plugins
* Distribute UMD as common js file to support bundled environments AND `<script>` tags

Author: Mark Kennedy

.babelrc.js

@@ -7,7 +7,7 @@ module.exports = {
                 useBuiltIns: 'usage',
                 corejs: 3,
                 targets: {
-                    browsers: ['last 2 versions', 'ie >= 11'],
+                    browsers: ['last 2 versions'],
                 },
             },
         ],