tracks/haskell/config.json in trackler-2.2.1.72 vs tracks/haskell/config.json in trackler-2.2.1.73

@@ -30,9 +30,18 @@
       "difficulty": 1,
       "topics": [
       ]
     },
     {
+      "uuid": "5bf7612c-427e-484d-bc67-8553fac4f64d",
+      "slug": "rail-fence-cipher",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 1,
+      "topics": [
+      ]
+    },
+    {
       "uuid": "6cbb7841-9d96-4528-88e3-6e98a450fd7c",
       "slug": "space-age",
       "core": false,
       "unlocked_by": null,
       "difficulty": 1,