update the master branch to the latest

src/components/menu/menu-group.vue

@@ -0,0 +1,33 @@
+<template>
+    <li :class="[prefixCls + '-item-group']">
+        <div :class="[prefixCls + '-item-group-title']" :style="groupStyle">{{ title }}</div>
+        <ul><slot></slot></ul>
+    </li>
+</template>
+<script>
+    import mixin from './mixin';
+    const prefixCls = 'ivu-menu';
+
+    export default {
+        name: 'MenuGroup',
+        mixins: [ mixin ],
+        props: {
+            title: {
+                type: String,
+                default: ''
+            }
+        },
+        data () {
+            return {
+                prefixCls: prefixCls
+            };
+        },
+        computed: {
+            groupStyle () {
+                return this.hasParentSubmenu && this.mode !== 'horizontal' ? {
+                    paddingLeft: 43 + (this.parentSubmenuNum - 1) * 28 + 'px'
+                } : {};
+            }
+        }
+    };
+</script>