fix(Footer): remove hardcoded default slot

Author: xidedix

src/components/Footer/Footer.vue

@@ -1,15 +1,6 @@
 <template>
   <footer :class="classList">
-    <slot>
-      <div>
-        <a href="https://coreui.io">CoreUI</a>
-        <span>&copy; 2018 creativeLabs.</span>
-      </div>
-      <div class="ml-auto">
-        <span>Powered by</span>
-        <a href="https://coreui.io">CoreUI for Vue</a>
-      </div>
-    </slot>
+    <slot>Footer</slot>
   </footer>
 </template>