This adds an internal method NodeBackend.setTransport that can take any module or object that looks like the http object. This is actually required by getsentry/sentry-electron#73 to use the electron.net module instead of node's own http implementation.

Since we do not have a clear design specification for transports yet, this API should be considered internal for now.

Details

Usually, we would add a transport option to the SDKs, just like raven-node and raven-js already have it. However, this approach would have two significant drawbacks:

1. There is no way we can set an option in the Electron frontend which will only be used by the Node backend and not by the Browser backend (actually, there is one, but it is super dirty).
2. I do not want to export Raven's transport interface to the "user" just now. The interface seems like the wrong layer of abstraction.

Instead, we can now manually set a transport to the backend instance directly using the setTransport setter. It needs to implement the exact signature of http.request.

For an example, have a look at ElectronBackend.