Support Azure managed disks
We would like to use the docker+machine executor in an restricted environment where public ip's cannot be used at all (prohibited by policies). Currently the driver tries to create an storage account with public access enabled.
Rancher's fork does have an option to use manged disks instead: https://github.com/rancher/machine/blob/master/drivers/azure/azure.go#L52
Creating machines using the Rancher fork does actually work but causes other issues as it does not seem to have stdout/stderr related fixes.