after adding the below script in package.json file it worked, thank you @George bhai 
“scripts”: {
“test”: “nyc mocha”,
“start”: “node ./node_modules/nodemon/bin/nodemon.js ./index.js”
},
after adding the below script in package.json file it worked, thank you @George bhai
“scripts”: {
“test”: “nyc mocha”,
“start”: “node ./node_modules/nodemon/bin/nodemon.js ./index.js”
},