Form: required rule shouldn't care about model type

examples/docs/en-US/quickstart.md

@@ -176,6 +176,7 @@ Vue.use(Radio)
 Vue.use(RadioGroup)
 Vue.use(RadioButton)
 Vue.use(Checkbox)
+Vue.use(CheckboxButton)
 Vue.use(CheckboxGroup)
 Vue.use(Switch)
 Vue.use(Select)

examples/docs/zh-CN/quickstart.md

@@ -176,6 +176,7 @@ Vue.use(Radio)
 Vue.use(RadioGroup)
 Vue.use(RadioButton)
 Vue.use(Checkbox)
+Vue.use(CheckboxButton)
 Vue.use(CheckboxGroup)
 Vue.use(Switch)
 Vue.use(Select)

packages/form/src/form-item.vue

@@ -176,6 +176,11 @@
         this.validateState = 'validating';
 
         var descriptor = {};
+        if (rules && rules.length > 0) {
+          rules.forEach(rule => {
+            delete rule.trigger;
+          });
+        }
         descriptor[this.prop] = rules;
 
         var validator = new AsyncValidator(descriptor);