Use bootstrap cards for feedback pages

Change-Id: I811bf2f3ce2992b7110d6742069eb07f38bd5b37
diff --git a/templates/resend_mail.htm b/templates/resend_mail.htm
index 7f8557d..4bbcf80 100644
--- a/templates/resend_mail.htm
+++ b/templates/resend_mail.htm
@@ -1 +1,3 @@
-<h2>Another email has been sent to <?php echo $_SESSION['email']; ?>!</h2>
+<div class="alert alert-info" role="alert">
+    Another email has been sent to <?php echo $_SESSION['email']; ?>!
+</div>