Fix execute flag tests

Author: rreusser

src/components/sliders/attributes.js

@@ -56,6 +56,7 @@ var stepsAttrs = {
     },
     execute: {
         valType: 'boolean',
+        role: 'info',
         dflt: true,
         description: [
             'When true, the API method is executed. When false, all other behaviors are the same',

src/components/updatemenus/attributes.js

@@ -47,6 +47,7 @@ var buttonsAttrs = {
     },
     execute: {
         valType: 'boolean',
+        role: 'info',
         dflt: true,
         description: [
             'When true, the API method is executed. When false, all other behaviors are the same',

test/jasmine/tests/updatemenus_test.js

@@ -111,6 +111,7 @@ describe('update menus defaults', function() {
         expect(layoutOut.updatemenus[0].buttons[0]).toEqual({
             method: 'relayout',
             args: ['title', 'Hello World'],
+            execute: true,
             label: '',
             _index: 1
         });
@@ -135,6 +136,7 @@ describe('update menus defaults', function() {
         expect(layoutOut.updatemenus[0].buttons[0]).toEqual({
             method: 'relayout',
             args: ['title', 'Hello World'],
+            execute: true,
             label: '',
             _index: 1
         });