Update landing plugin commands.

src/landing/index.ts

@@ -5,9 +5,10 @@ export * from './widget';
 
 
 /**
- * The map of command ids used by the landing plugin.
+ * The command IDs used by the landing plugin.
  */
 export
-const cmdIds = {
-  open: 'landing-jupyterlab:open',
+namespace CommandIDs {
+  export
+  const open = 'landing-jupyterlab:open';
 };

src/landing/plugin.ts

@@ -26,7 +26,7 @@ import {
 } from '../services';
 
 import {
-  LandingModel, LandingWidget, cmdIds
+  CommandIDs, LandingModel, LandingWidget
 } from './';
 
 /**
@@ -56,7 +56,7 @@ export default plugin;
  */
 function activate(app: JupyterLab, pathTracker: IPathTracker, palette: ICommandPalette, services: IServiceManager, restorer: IInstanceRestorer): void {
   const category = 'Help';
-  const command = cmdIds.open;
+  const command = CommandIDs.open;
   const model = new LandingModel(services.terminals.isAvailable());
   const tracker = new InstanceTracker<LandingWidget>({ namespace: 'landing' });