basic PowerShell 7 compatibility

[schmoaaaaah]

This is more or less the bare minimum to get PowerShell 7 working. It might be helpful for people in #53.

I tested it against a Baramundi Instance using Self Signed Certificates using PowerShell 7 and 5. I only tested using the Get-bConnectInfo function as we only have a production setup. If someone could test it against a Instance with trusted Certificates that would be helpful though I don't believe that it should make problems.