Fixed warning when unmounting animated modals

Signed-off-by: Reid Mitchell <rmitchell@pivotal.io>

spec/pivotal-ui-react/modals/modals_spec.js

@@ -1,6 +1,7 @@
 import '../spec_helper';
 import {findByClass, findAllByClass, clickOn} from '../spec_helper';
 import {Modal, BaseModal} from '../../../src/react/modals';
+import AnimationMixin from 'pui-react-animation';
 
 let result;
 
@@ -238,6 +239,20 @@ describe('BaseModal', () => {
 
       expect(onHide).not.toHaveBeenCalled();
     });
+
+    describe('when animation is true', () => {
+      beforeEach(() => {
+        spyOn(AnimationMixin, 'componentWillUnmount').and.callThrough();
+      });
+
+      it('resets animation if unmounted before animation finishes', () => {
+        result = renderIntoDom({show: true, onHide, animation: true});
+        ReactDOM.unmountComponentAtNode(root);
+        MockRaf.next();
+
+        expect(AnimationMixin.componentWillUnmount).toHaveBeenCalled();
+      });
+    });
   });
 
   describe('acquireFocus', () => {

src/react/modals/modals.js

@@ -76,6 +76,7 @@ export class BaseModal extends mixin(React.PureComponent).with(Animation) {
   }
 
   componentWillUnmount() {
+    if (super.componentWillUnmount) super.componentWillUnmount();
     const document = this.props.getDocument();
     if (typeof document !== 'object') return;
     document.removeEventListener('keydown', this.onKeyDown);