Green checkmarks added to Video and Zipline challenges view for completed challenges

server/views/challenges/showVideo.jade

@@ -3,6 +3,9 @@ block content
     .row
         .col-xs-12.col-sm-12.col-md-4
             h4.text-center.challenge-instructions-title= name
+                if (isCompleted)
+                    |  
+                    i.ion-checkmark-circled.text-primary(title="Completed")
             hr
             ol
                 for step, index in description

server/views/challenges/showZiplineOrBasejump.jade

@@ -3,6 +3,9 @@ block content
     .row
         .col-md-4
             h4.text-center.challenge-instructions-title= name
+                 if (isCompleted)
+                    |  
+                    i.ion-checkmark-circled.text-primary(title="Completed")           
             hr
             ol
                 for step, index in description