[103] Remove the word "button"

Author: tianlunlee

mdc_100_series/lib/login.dart

@@ -68,7 +68,7 @@ class _LoginPageState extends State<LoginPage> {
                     _passwordController.clear();
                   },
                 ),
-                // TODO: Add an elevation to the NEXT button (103)
+                // TODO: Add an elevation to NEXT (103)
                 // TODO: Add a beveled rectangular border to NEXT (103)
                 RaisedButton(
                   child: Text('NEXT'),