Dependency updates

[cbodin]

Most of the dependencies were pretty outdated and had some security vulnerabilities.

Changes:

• Added test to verify certificate chain after generation.
• Bumped the node version to >= 12 in the engines section in package.json, lowest version currently supported.
• Removed the dependency of random-int as it's not really needed.
• Removed the is-ip package and used the ip-regex package directly to keep browser support.
• Updated all packages to the latest version except ip-regex as version 5 is pure ESM.

[Subash]

Thank You