NodeJS v14

With NodeJS v14.x becoming the current LTS version, I now develop and test my plugins against the latest v14 of NodeJS. A warning message will be issued when you run another version. This other version might just work, but I recommend to use the latest LTS version.
Note that, when upgrading (or downgrading) to different major NodeJS version, you need to re-build any package containing C++ components. Typically, this involves uninstalling and re-installing the package.

Bump Dependencies

• NodeJS v14.15.0
• homebridge-lib v4.8.0.