fix(item): sliding item's width must be 100%

#closes 6239

src/components/item/item-sliding.scss

@@ -8,6 +8,8 @@ ion-item-sliding {
   position: relative;
   display: block;
   overflow: hidden;
+
+  width: 100%;
 
   .item {
     position: static;

src/components/virtual-scroll/test/sliding-item/index.ts

@@ -0,0 +1,58 @@
+import {Component, ViewChild, ElementRef} from '@angular/core';
+import {ionicBootstrap, Platform} from '../../../../../src';
+
+
+@Component({
+  templateUrl: 'main.html'
+})
+class E2EPage {
+  items: any[] = [];
+  webview: string;
+
+  @ViewChild('content') content: ElementRef;
+
+  constructor(platform: Platform) {
+    for (var i = 0; i < 200; i++) {
+      this.items.push({
+        value: i,
+        someMethod: function() {
+          return '!!';
+        }
+      });
+    }
+
+    if (platform.is('ios')) {
+      if (window.indexedDB) {
+        this.webview = ': WKWebView';
+
+      } else {
+        this.webview = ': UIWebView';
+      }
+    }
+  }
+
+  headerFn(record: any, index: number, records: any[]) {
+    if (index % 4 === 0) {
+      return index + ' is divisible by 4';
+    }
+
+    return null;
+  }
+
+  reload() {
+    window.location.reload(true);
+  }
+
+}
+
+
+@Component({
+  template: '<ion-nav [root]="root"></ion-nav>'
+})
+class E2EApp {
+  root = E2EPage;
+}
+
+ionicBootstrap(E2EApp, null, {
+  prodMode: true
+});

src/components/virtual-scroll/test/sliding-item/main.html

@@ -0,0 +1,33 @@
+<ion-navbar *navbar>
+  <ion-title>Virtual Scroll{{webview}}</ion-title>
+  <ion-buttons end>
+    <button (click)="reload()">
+      Reload
+    </button>
+  </ion-buttons>
+</ion-navbar>
+
+<ion-content>
+
+
+  <ion-list [virtualScroll]="items"
+            [headerFn]="headerFn">
+
+    <ion-item-divider *virtualHeader="let header">
+      Header: {{header}}
+    </ion-item-divider>
+
+    <ion-item-sliding *virtualItem="let item">
+      <ion-item>Item: {{item.value}} {{item.someMethod()}}</ion-item>
+      <ion-item-options>
+        <button>Archive</button>
+      </ion-item-options>
+      <ion-item-options side="left">
+        <button danger>Remove</button>
+      </ion-item-options>
+    </ion-item-sliding>
+
+  </ion-list>
+
+
+</ion-content>