add CellSwitch component

packages/switch-cell/index.vue

@@ -0,0 +1,32 @@
+<template>
+  <van-cell :title="title" class="van-switch-cell">
+    <van-switch :value="value" @input="$emit('input', $event)" :disabled="disabled" :loading="loading" />
+  </van-cell>
+</template>
+
+<script>
+import Cell from '../cell';
+import Switch from '../switch';
+
+export default {
+  name: 'van-switch-cell',
+
+  components: {
+    [Cell.name]: Cell,
+    [Switch.name]: Switch
+  },
+
+  props: {
+    title: String,
+    value: Boolean,
+    loading: Boolean,
+    disabled: Boolean
+  },
+
+  watch: {
+    value() {
+      this.$emit('change', this.value);
+    }
+  }
+};
+</script>