Set default value for user_scheme (#525)

Author: optik-aper

Diff for: vultr/resource_vultr_bare_metal_server.go

@@ -124,6 +124,7 @@ func resourceVultrBareMetalServer() *schema.Resource {
 				Type:     schema.TypeString,
 				Optional: true,
 				ForceNew: true,
+				Default:  "root",
 			},
 			"app_variables": {
 				Type:     schema.TypeMap,

Diff for: vultr/resource_vultr_instance.go

@@ -196,6 +196,7 @@ hostname on UI or API issues a reinstall of the OS.`,
 				Type:     schema.TypeString,
 				Optional: true,
 				ForceNew: true,
+				Default:  "root",
 			},
 			"app_variables": {
 				Type:     schema.TypeMap,