provider/digitaocean: Test that droplets are indempotent (#13883)

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

builtin/providers/digitalocean/resource_digitalocean_droplet_test.go

@@ -41,6 +41,11 @@ func TestAccDigitalOceanDroplet_Basic(t *testing.T) {
 					resource.TestCheckResourceAttr(
 						"digitalocean_droplet.foobar", "user_data", "foobar"),
 				),
+				Destroy: false,
+			},
+			{
+				Config:   testAccCheckDigitalOceanDropletConfig_basic(rInt),
+				PlanOnly: true,
 			},
 		},
 	})