message: Tested the crumb is frozen
  The set state shouldn't re-render
diff: @@ -3,7 +3,7 @@ import 'mocha';
  import { StateNavigator } from 'navigation';
  import { NavigationHandler } from 'navigation-react';
  import { NavigationMotion } from 'navigation-react-mobile';
  -import React from 'react';
  +import React, {useState} from 'react';
  import ReactDOM from 'react-dom';
  import { JSDOM } from 'jsdom';
  @@ -990,4 +990,43 @@ describe('NavigationMotion', function () {
  }
  })
  });
  +
  + describe('Crumb set state', function () {
  + it('should not render', function(){
  + var stateNavigator = new StateNavigator([
  + { key: 'sceneA' },
  + { key: 'sceneB', trackCrumbTrail: true },
  + ]);
  + stateNavigator.navigate('sceneA');
  + var {sceneA, sceneB} = stateNavigator.states;
  + var update;
  + var SceneA = () => {
  + var [updated, setUpdated] = useState(false)
  + update = setUpdated;
  + return <div id='sceneA' data-updated={updated} />;
  + };
  + var SceneB = () => <div id="sceneB" />;
  + sceneA.renderScene = () => <SceneA />;
  + sceneB.renderScene = () => <SceneB />;
  + var container = document.createElement('div');
  + ReactDOM.render(
  + <NavigationHandler stateNavigator={stateNavigator}>
  + <NavigationMotion>
  + {(_style, scene, key) => (
  + <div className="scene" id={key} key={key}>{scene}</div>
  + )}
  + </NavigationMotion>
  + </NavigationHandler>,
  + container
  + );
  + stateNavigator.navigate('sceneB');
  + update(true);
  + try {
  + var scene = container.querySelector<HTMLDivElement>("#sceneA");
  + assert.strictEqual(scene.dataset.updated, 'false');
  + } finally {
  + ReactDOM.unmountComponentAtNode(container);
  + }
  + })
  + });
  });
  