Add touchbar smoke tests

Author: MarshallOfSound

test-smoke/electron/test/main.ts

@@ -1146,5 +1146,6 @@ win4.loadURL("http://github.com");
 const unusedTouchBar = new TouchBar({
   items: [
     new TouchBar.TouchBarButton({ label: '' }),
+    new TouchBar.TouchBarLabel({ label: '' }),
   ],
 });

test/output_spec.js

@@ -21,7 +21,6 @@ describe('Definition File', function () {
     spawn('node', ['cli.js', '-o=electron.d.ts'], {
       cwd: path.resolve(__dirname, '..')
     }).on('exit', () => done())
-    done()
   })
 
   it('should output a electron.d.ts file', () => {