infrakit: removed vm-lib from arguments

Instead pass the directory where to find initrd/vmlinuz via the
"Moby" entry in the instance JSON config.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

tools/infrakit.hyperkit/hyperkit.json

@@ -7,7 +7,7 @@
         "Instance": {
             "Plugin": "instance-hyperkit",
             "Properties": {
-                "Moby": "default",
+                "Moby": "./vms/default",
                 "Disk" : 512,
                 "CPUs" : 2,
                 "Memory" : 1024