minor code style enhancements

Author: chisler

backend/installGlobalHook.js

@@ -190,10 +190,10 @@ function installGlobalHook(window: Object) {
       // FIXME: Do we need to report buildType of smth other than ReactDOM?
       // Currently we overwrite buildType with each injected renderer's type
       var reactBuildType = duplicatedReact
-        ? "duplicated"
+        ? 'duplicated'
         : detectReactBuildType(renderer);
 
-      hook.emit("renderer", { id, renderer, reactBuildType });
+      hook.emit('renderer', { id, renderer, reactBuildType });
       return id;
     },
     _listeners: {},