import BrowserAnimationsModule in the preview

Fixes #32

Author: ocombe

packages/angular/preview/src/app/app.module.ts

@@ -1,5 +1,5 @@
 import { NgModule } from '@angular/core';
-import { BrowserModule } from '@angular/platform-browser';
+import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
 
 import { AppComponent } from './app.component';
 import { DocsComponent } from './docs/docs.component';
@@ -8,7 +8,7 @@ import { LazyLoadComponent } from './lazy-load/lazy-load.component';
 
 @NgModule({
   declarations: [AppComponent, LazyLoadComponent, SafeHtmlPipe, DocsComponent],
-  imports: [BrowserModule],
+  imports: [BrowserAnimationsModule],
   bootstrap: [AppComponent]
 })
 export class AppModule {