chore: rework client example to omit log.Fatal, breaks defer (#489)

Signed-off-by: James Hillyerd <james@hillyerd.com>

pkg/rest/client/example_test.go

@@ -16,17 +16,18 @@ func Example() {
 	baseURL, teardown := exampleSetup()
 	defer teardown()
 
+	err := func() error {
 		// Begin by creating a new client using the base URL of your Inbucket server, i.e.
 		// `localhost:9000`.
 		restClient, err := client.New(baseURL)
 		if err != nil {
-		log.Fatal(err)
+			return err
 		}
 
 		// Get a slice of message headers for the mailbox named `user1`.
 		headers, err := restClient.ListMailbox("user1")
 		if err != nil {
-		log.Fatal(err)
+			return err
 		}
 		for _, header := range headers {
 			fmt.Printf("ID: %v, Subject: %v\n", header.ID, header.Subject)
@@ -35,7 +36,7 @@ func Example() {
 		// Get the content of the first message.
 		message, err := headers[0].GetMessage()
 		if err != nil {
-		log.Fatal(err)
+			return err
 		}
 		fmt.Printf("\nFrom: %v\n", message.From)
 		fmt.Printf("Text body:\n%v", message.Body.Text)
@@ -43,7 +44,14 @@ func Example() {
 		// Delete the second message.
 		err = headers[1].Delete()
 		if err != nil {
-		log.Fatal(err)
+			return err
+		}
+
+		return nil
+	}()
+
+	if err != nil {
+		log.Print(err)
 	}
 
 	// Output: