fix tests

Author: broothie

command_test.go

@@ -33,7 +33,7 @@ func ExampleNewCommand() {
 	// Usage:
 	//   server [flags] [sub-command]
 	//
-	// Sub-command:
+	// Sub-commands:
 	//   proxy: Proxy requests to another server.
 	//
 	// Flags:

help_test.go

@@ -86,7 +86,7 @@ func TestCommand_renderHelp(t *testing.T) {
 				Usage:
 				  test [flags] [sub-command]
 
-				Sub-command:
+				Sub-commands:
 				  some-command: some command
 
 				Flags:

options_test.go

@@ -130,7 +130,7 @@ func ExampleAddSubCmd() {
 	// Usage:
 	//   server [sub-command]
 	//
-	// Sub-command:
+	// Sub-commands:
 	//   start: Start the server
 }