refactor(button): added some primary attributes to the tests to make sure the styling is right

Fixed the button primary clear, closes #354

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

@@ -10,6 +10,11 @@
     <button class="activated">Default.activated</button>
   </p>
 
+  <p>
+    <button primary>Primary</button>
+    <button primary class="activated">Primary.activated</button>
+  </p>
+
   <p>
     <button secondary>Secondary</button>
     <button secondary class="activated">Secondary.activated</button>