update following npm audit fix

[temyers]

Updates packages for known vulnerabilities.

$ npm install
audited 360 packages in 2.093s
found 2 vulnerabilities (1 moderate, 1 high)
  run `npm audit fix` to fix them, or `npm audit` for details
$ npm audit fix
added 2 packages from 9 contributors, removed 1 package and updated 6 packages in 2.967s
fixed 2 of 2 vulnerabilities in 360 scanned packages

This PR does not update the aws-sdk version, to avoid any risk of breaking stuff.