Uncommented web-animations-js from polyfill.ts

Author: HowdyChad

angular/src/polyfills.ts

@@ -37,7 +37,7 @@ import 'core-js/es6/set';
 // import 'classlist.js';  // Run `npm install --save classlist.js`.
 
 /** IE10 and IE11 requires the following to support `@angular/animation`. */
-//import 'web-animations-js';  // Run `npm install --save web-animations-js`.
+import 'web-animations-js';  // Run `npm install --save web-animations-js`.
 
 
 /** Evergreen browsers require these. **/