Removed prop duration to avoid invalid html attributes for Toast (gro…

…mmet#1813)

* Removed prop duration from Toast component to avoid invalid html attributes on prop tranfer

* Increased test coverage

__tests__/components/Toast-test.js

@@ -11,6 +11,7 @@ jest.mock('react-dom');
 
 describe('Toast', () => {
   it('has correct default options', () => {
+    document.body.innerHTML = '<div></div>';
     const component = renderer.create(
       <Toast>
         <span>

src/js/components/Toast.js

@@ -59,6 +59,7 @@ class ToastContents extends Component {
     const { closing } = this.state;
 
     // removing context props to avoid invalid html attributes on prop transfer
+    delete rest.duration;
     delete rest.history;
     delete rest.intl;
     delete rest.router;