npm commands don't execute in git bash / windows

[oliverfoster]

Suggest changing from:

{
    "build-js": "./node_modules/webpack/bin/webpack.js --mode=production",
    "build-css": "./node_modules/node-sass/bin/node-sass src/browser.sass dist/react-keyed-file-browser.css",
    "build": "npm run build-js; npm run build-css",
}

To a more system agnostic syntax:

{
    "build-js": "./node_modules/.bin/webpack --mode=production",
    "build-css": "./node_modules/.bin/node-sass src/browser.sass dist/react-keyed-file-browser.css",
    "build": "npm run build-js && npm run build-css",
}

This will then work with git bash, unix-style terminals and the cmd prompt. This is as either the bash script or cmd script will be executed appropriately using those new paths and that all systems understand the && syntax rather than the unix ;.