fix(Tabset.vue): Correct the wrong use of camelCase name for "v-el:"

wusisu · wusisu · commit 9b0d3bb64368 · 2016-03-09T09:43:38.000+08:00
The warning in vue@1.0.17 is annoying.

fix Issue#133
diff --git a/src/Tabset.vue b/src/Tabset.vue
@@ -16,7 +16,7 @@
      </ul>
 
      <!-- Tab panes -->
-     <div class="tab-content" v-el:tabContent>
+     <div class="tab-content" v-el:tab-content>
         <slot></slot>
      </div>
   </div>
