issue: addresses #569

Author: johnalotoski

cardano-lib/default.nix

@@ -22,7 +22,7 @@ let
         }
       ];
     };
-  in toFile "topology.yaml" (toJSON topology);
+  in toFile "topology.json" (toJSON topology);
 
   mkEdgeTopologyP2P = {
     edgeNodes ? [{addr = "127.0.0.1"; port = 3001;}]
@@ -54,7 +54,7 @@ let
       ];
     };
   in
-    toFile "topology.yaml" (toJSON topology);
+    toFile "topology.json" (toJSON topology);
 
   mkTopology = env: let
     legacyTopology = mkEdgeTopology {