Can create surveys

lib/helpers/posts_helper.dart

@@ -158,6 +158,11 @@ class PostsHelper {
             "time-end", (post.timeEnd.millisecondsSinceEpoch / 1000).floor());
         break;
 
+      case PostKind.SURVEY:
+        request.addString("question", post.survey.question);
+        request.addString("answers", post.survey.answers.join("<>"));
+        break;
+
       default:
         throw Exception("Unsupported post type :" + post.kind.toString());
         break;