SSL error sending messages to Slack

[szaffarano]

Is your feature request related to a problem? Please describe.

Depending on the system configuration where I run edr monitor, it's possible to get the following error when trying to send messages to Slack

urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1000)>

This is because the system does not have the latest CA files and hence the HTTP request fails due to a TLS handshake error.

Describe the solution you'd like

A possible solution would be to optionally allow the user to use certifi's Root CAs, which are supposed to be updated and are safe to use.

Describe alternatives you've considered

Other option is to update the system CA, but it's not always possible.

Additional context

N/A

Would you be willing to contribute this feature?

Yes, I'm about to submit a PR with the proposed solution.