New Microsoft Azure docker-machine driver

The new driver uses Azure Resource Manager APIs and offers a lot
more functionality compared to the old Azure driver. It is also
easier to authenticate and does not require user to create and place
certificate files. It only has a single required argument.

This is a breaking change: The new driver cannot work with machines
created with the older Azure driver and vice versa (as the APIs are
entirely different and resources are not shared between old/new azure
APIs).

The new driver addresses many issues about the azure driver reported
so far.

This resolves #2742, resolves #1368, resolves #1142, resolves #2236,
resolves #2408, resolves #1126, resolves #774.

Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>

libmachine/drivers/plugin/localbinary/plugin.go

@@ -17,7 +17,7 @@ var (
 	// plugin server.
 	defaultTimeout               = 10 * time.Second
 	CurrentBinaryIsDockerMachine = false
-	CoreDrivers                  = [...]string{"amazonec2", "digitalocean",
+	CoreDrivers                  = [...]string{"amazonec2", "azure", "digitalocean",
 		"exoscale", "generic", "google", "hyperv", "none", "openstack",
 		"rackspace", "softlayer", "virtualbox", "vmwarefusion",
 		"vmwarevcloudair", "vmwarevsphere"}