Use of 'const' in strict mode

Below is how the issue was handled in Git, trying this may help you resolve the issue.

If you have a working version prior to update go to that installation and use:

npm shrinkwrap 
or npm shrinkwrap --dev

then a new file will be created

npm-shrinkwrap.json

Check that file and make sure dependencies are created. Normally this file has all the existing dependencies. Put that file in the folder which you run npm install inside. NPM will use the old versions and should work.

As an alternative you can remove all unrelated dependencies and keep only node-sass with request dependency.

"node-sass": {
        "version": "2.1.1",
        "from": "node-sass@>=2.0.1 <3.0.0",
        "resolved": "https://registry.npmjs.org/node-sass/-/node-sass-2.1.1.tgz",
        "dependencies": {
          "request": {
            "version": "2.79.0",
            "from": "request@>=2.53.0 <3.0.0",
            "resolved": "https://registry.npmjs.org/request/-/request-2.79.0.tgz",
          },
        }
      },