Fix checkmark on second assessment run

mentoring/public/js/mentoring_assessment_view.js

@@ -10,6 +10,7 @@ function MentoringAssessmentView(runtime, element, mentoring) {
     function cleanAll() {
         // clean checkmark state
         checkmark.removeClass('checkmark-correct icon-ok fa-check');
+        checkmark.removeClass('checkmark-partially-correct icon-ok fa-check');
         checkmark.removeClass('checkmark-incorrect icon-exclamation fa-exclamation');
 
         /* hide all children */

mentoring/templates/xml/mentoring_assessment.xml

-<mentoring url_name="{{ url_name }}" display_name="Nav tooltip title" weight="1" mode="assessment">
+<mentoring url_name="{{ url_name }}" display_name="Nav tooltip title" weight="1" mode="assessment" max_attempts="10">
     <title>Default Title</title>
     <shared-header>
         <p>This paragraph is shared between <strong>all</strong> questions.</p>