Remove (Grade Me!) template until it can be productized.

common/lib/xmodule/xmodule/templates/html/grade_me.yaml

----
-metadata:
-    display_name: (Grade Me!)  Button
-data: |
-      <p>By clicking the button below, you assert that you have completed the course in its entirety.</p>
-      
-      <input type=button value="Yes, I Agree." id="User_Verify_Button" style="margin-bottom: 20px;" />
-      <p class="verify-button-success-text" style="font-weight: bold; color: #008200;"></p>
-      
-      <script type="text/javascript">
-        var success_message = "Your grading and certification request has been received, <br />if you have passed, your certificate should be available in the next 20 minutes.";
-        document.getElementById('User_Verify_Button').addEventListener("click",
-        function(event) {
-          (function(event) {
-            var linkcontents = $('a.user-link').contents();
-            $.ajax({
-              type:     'POST',
-              url:      '/request_certificate',
-              data:     {'course_id': $$course_id},
-              success:  function(data) {
-                $('.verify-button-success-text').html(success_message);
-              }
-            });
-          }).call(document.getElementById('User_Verify_Button'), event);
-        });
-      </script>