The problem is likely missing quotes around the glob path.
Change this (not working): "lint": "eslint ./src/**/*.js"
To this (working): "lint": "eslint './src/**/*.js'"
The ESLint docs say this:
Please note that when passing a glob as a parameter, it is expanded by your shell. The results of the expansion can vary depending on your shell, and its configuration. If you want to use node glob syntax, you have to quote your parameter (using double quotes if you need it to run in Windows)
And some Googling turned up this thread on GitHub: