fix(segment): add ion-content back in for the sake of snapshot

ionic/components/segment/test/basic/main.html

@@ -25,7 +25,7 @@
   </ion-segment>
 </ion-toolbar>
 
-<div padding>
+<ion-content padding>
   <div>Are we friends or enemies? <b>{{ relationship }}</b></div>
 
   <h4>Map mode: NgControl</h4>
@@ -80,7 +80,7 @@
   </ion-segment>
 
   <p>Model Style: <b>Model {{ modelStyle }}</b></p>
-</div>
+</ion-content>
 
 <ion-toolbar position="bottom" primary>
   <ion-segment [(ng-model)]="appType" light>