Unable to authenticate with Ring (unable to verify the first certificate)
# Bug Report

### Describe the Bug
Unable to authenticate with Ring

### To Reproduce
Steps to reproduce the behavior:
Start Homebridge (v1.3.4, node v14.16.1 Raspbian GNU/Linux Buster (10))
Get token using ring-auth-cli:
This CLI will provide you with a refresh token which you can use to configure ring-client-api and homebridge-ring.
Email: xxxxxxxxx
Password: xxxxxxxxx
The token gets generated after a long wait for the 2FA (sometimes 10 minutes).

### Expected behavior
The plugin should authenticate with ring servers.

### Screenshots/Logs
Getting the following error every 5 seconds:
[Ring] Failed to reach Ring server at https://oauth.ring.com/oauth/token. unable to verify the first certificate. Trying again in 5 seconds...

### Homebridge Ring Config
{
            "refreshToken": "xxxxxxxxxxxxxxxx",
            "alarmOnEntryDelay": true,
            "showPanicButtons": true,
            "sendCameraMotionNotificationsToTv": false,
            "sendDoorbellMotionNotificationsToTv": false,
            "platform": "Ring"
}

### Environment
<!-- ✍️edit: -->
 - OS: Raspbian GNU/Linux Buster (10)
 - Node.js: v14.16.1
 - NPM: v7.11.1
 - homebridge-ring: 9.18.0
 - homebridge: v1.3.4
 - hoobs: N/A
