[update] support plugins

what:
why:
how:

__tests__/dispatcher/index.js

@@ -193,6 +193,13 @@ describe('dispatcher', () => {
       expect(dispatcher.readySync).toBe(true);
       dispatcher.destroy();
     });
+    test('support plugins too', () => {
+      const dispatcher = new Dispatcher({
+        wrapper: document.createElement('div'),
+        plugins: ['normalInstall']
+      }, {});
+      expect(dispatcher.plugins.normalInstall.__id).toBe('normalInstall');
+    });
   });
 
   describe('_getTopLevel', () => {

src/dispatcher/index.js

@@ -99,6 +99,12 @@ export default class Dispatcher {
     this.videoConfigReady = false;
     // create the videoconfig
     this.videoConfig = new VideoConfig(this, config);
+    // support both plugin and plugins here as people often cofuse both
+    // $FlowFixMe: we support plugins here, which should be illegal
+    if(isArray(config.plugins) && !isArray(config.plugin)) {
+      config.plugin = config.plugins;
+      delete config.plugins;
+    }
     this._initUserPlugin(config.plugin);
     this.order.forEach(key => this.plugins[key].__init(this.videoConfig));
     this.videoConfig.lockKernelProperty();