Error: Cannot find module 'once' - node.js

Question

Error: Cannot find module 'once'
at Function.Module._resolveFilename (module.js:337:15)
at Function.Module._load (module.js:287:25)
at Module.require (module.js:366:17)
at require (module.js:385:17)
at Object.<anonymous> (/usr/local/lib/node_modules/nodemon/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/got/node_modules/duplexify/node_modules/end-of-stream/index.js:1:74)
at Module._compile (module.js:435:26)
at Object.Module._extensions..js (module.js:442:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:311:12)
at Module.require (module.js:366:17)
at require (module.js:385:17)
I'm getting this error when I try running my server.js with nodemon. I looked in my node_modules folder and there is a 'once' folder in there. I tried
rm -rf node_modules
npm install
to remove the entire node_modules folder and reinstall but it didn't work. I also did
npm install --save once
and still didn't work.
This is package.json
{
"name": "FullMean_Friends",
"version": "0.0.1",
"scripts": {
"start": "node server.js"
},
"dependencies": {
"body-parser": "latest",
"express": "~4.2.0",
"mongoose": "latest"
}
}