无法部署到heroku - npm启动错误

Question

尝试将我的应用部署到heroku并且构建成功。不幸的是，Web应用程序不起作用。我得到的错误是关于npm start。

"scripts": {
"test": "echo \"Error: no test specified\" && exit 1,",
"start": "./index.js"
},

我假设这可能与我的package.js文件夹有关。我在脚本中添加了以下内容。

> rock-paper-scissors@1.0.0 start /Users/briankaty1/Dropbox/rock-paper-  scissors
> ./index.js

  sh: ./index.js: Permission denied
  npm ERR! code ELIFECYCLE
  npm ERR! errno 126
  npm ERR! rock-paper-scissors@1.0.0 start: `./index.js`
  npm ERR! Exit status 126
  npm ERR!
  npm ERR! Failed at the rock-paper-scissors@1.0.0 start script.
  npm ERR! This is probably not a problem with npm. There is likely additional     logging output above.
  npm WARN Local package.json exists, but node_modules missing, did you mean    to install?

 npm ERR! A complete log of this run can be found in:
 npm ERR!     /Users/briankaty1/.npm/_logs/2018-04-10T17_33_14_741Z-debug.log

当我检查是否可以在本地运行脚本时，我收到以下错误。

version: '3'

services:
  myserver:
    image: myserver
    build:
      context: .\myserver
      dockerfile: Dockerfile
    volumes:
      - folder:c:\folder

volumes:
  folder:

我很确定我有index.js文件的路径是正确的。最终，我想在heroku上运行这个应用程序。