We have a Azure IoT hub based cloud infrastructure which we use to deliver the packages/file till the devices. Devices have our own properitery agents running. I am using mender client in my yocto embedded Linux based devcies. My question is do i need the Mender server as mandatory to give the updates to the mender client. Can i use my own delivery mechanism and mender client can just look into a particular directory to get the platform updates (Mender Artifact).