Update auth0-js + node-fetch

[stevehobbsdev]

Changes

This PR performs 2 dependency updates:

• Forcing node-fetch to resolve a vulnerability in the version used by React
  React > fbjs > isomorphic-fetch > node-fetch (link)
• Update auth0-js to v9.16.2 (latest)

References

Testing

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All code quality tools/guidelines have been run/followed
• All relevant assets have been compiled

[stevehobbsdev]

The build is failing due to a transitive dependency (I think from Auth0.js) spewing ES6 into the compiled output, which then fails when UglifyJS tries to minify it (it can't handle ES6 syntax). Still investigating..

[stevehobbsdev]

I've updated auth0-js again to fix the build. This latest version reverts the update to crypto-js which doesn't work with Lock thanks to it dropping polyfill support for the Crypto API.