fix: package.json to reduce vulnerabilities
fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:ws:20160624
- https://snyk.io/vuln/npm:ws:20160104
- https://snyk.io/vuln/npm:ms:20151024

Latest report for slashattack89/deepstream.io:
https://snyk.io/test/github/slashattack89/deepstream.io
slashattack89/deepstream.io,slashattack89/deepstream.io