Update test to show that topic updates work as well

Signed-off-by: Timo Sand <[email protected]>

Author: deiga

github/resource_github_repository_test.go

@@ -393,20 +393,29 @@ func TestAccGithubRepository(t *testing.T) {
 			}
 		`, testRepoName)
 
-		check := resource.ComposeTestCheckFunc(
-			resource.TestCheckResourceAttr(
-				"github_repository.test", "topics.#",
-				"2",
-			),
-		)
-
 		resource.Test(t, resource.TestCase{
 			PreCheck:          func() { skipUnauthenticated(t) },
 			ProviderFactories: providerFactories,
 			Steps: []resource.TestStep{
 				{
 					Config: config,
-					Check:  check,
+					Check: resource.ComposeTestCheckFunc(
+						resource.TestCheckResourceAttr(
+							"github_repository.test", "topics.#",
+							"2",
+						),
+					),
+				},
+				{
+					Config: strings.Replace(config,
+						`topics			= ["terraform", "testing"]`,
+						`topics			= ["terraform", "testing", "extra-topic"]`, 1),
+					Check: resource.ComposeTestCheckFunc(
+						resource.TestCheckResourceAttr(
+							"github_repository.test", "topics.#",
+							"3",
+						),
+					),
 				},
 			},
 		})