Sign the macOS builds

[NitriKx]

We should set up the Apple developer account and then use it to sign the releases

[demosdemon]

the electron builder apparently does this automatically if you have a valid key in your keychain

https://lbc-releases.s3.amazonaws.com/cloudRIG/cloudRIG-0.0.1-alpha.11.dmg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA3YJ63FBRCJXFKWHX%2F20190810%2Fus-east-2%2Fs3%2Faws4_request&X-Amz-Date=20190810T164216Z&X-Amz-Expires=31536000&X-Amz-SignedHeaders=host&X-Amz-Signature=87ffd900f26533277e3a05cb9a573bb3d671cb27f64120b7c49ca506060e2e58

[NitriKx]

I've also added entitlements (for future App Store submission) and notorization

[NitriKx]

The problem today is that we want to change the Apple team for the app signature, and the auto updated doesn’t like that.