increased image preview size

app/assets/stylesheets/common.scss

@@ -764,8 +764,8 @@ input.git_clone_url {
     background:#eee;
     text-align:center;
     img {
-      padding:100px;
-      max-width:300px;
+      padding:50px;
+      max-width:400px;
     }
   }
 }