Merge #209: Lightning loop

e9204946d4 lightning-loop: add tests (nixbitcoin)
491d83a658 lightning-loop: add module (nixbitcoin)
8f3588b13f lnd: higher attempt limit for less-powerful machines (nixbitcoin)
1bb801ad7b lightning-loop: add pkg (nixbitcoin)

Pull request description:

ACKs for top commit:
  jonasnick:
    ACK e9204946d4

Tree-SHA512: cc8bb85978350dd530c3c8d2c9aca5ddc4ab1f72cdd27d031bb303eca1d9473f18e45bc119c62bb2991faa32b3e1d42e4439f02a56ab3a6b975b0bd491195604

modules/presets/secure-node.nix

@@ -161,6 +161,12 @@ in {
     };
     services.tor.hiddenServices.lnd = mkIf cfg.lnd.enable (mkHiddenService { port = cfg.lnd.onionport; toHost = cfg.lnd.listen; });
 
+    # lightning-loop
+    services.lightning-loop = {
+      proxy = cfg.tor.client.socksListenAddress;
+      enforceTor = true;
+    };
+
     # liquidd
     services.liquidd = {
       rpcuser = "liquidrpc";