add tx confirmation model

lib/model/index.js

@@ -10,5 +10,6 @@ Model.Email = require('./email');
 Model.TxNote = require('./txnote');
 Model.Session = require('./session');
 Model.PushNotificationSub = require('./pushnotificationsub');
+Model.TxConfirmationSub = require('./txconfirmationsub');
 
 module.exports = Model;

lib/model/txconfirmationsub.js

@@ -0,0 +1,30 @@
+'use strict';
+
+function TxConfirmationSub() {};
+
+TxConfirmationSub.create = function(opts) {
+  opts = opts || {};
+
+  var x = new TxConfirmationSub();
+
+  x.version = 1;
+  x.createdOn = Math.floor(Date.now() / 1000);
+  x.copayerId = opts.copayerId;
+  x.txid = opts.txid;
+  x.isActive = true;
+  return x;
+};
+
+TxConfirmationSub.fromObj = function(obj) {
+  var x = new TxConfirmationSub();
+
+  x.version = obj.version;
+  x.createdOn = obj.createdOn;
+  x.copayerId = obj.copayerId;
+  x.txid = obj.txid;
+  x.isActive = obj.isActive;
+  return x;
+};
+
+
+module.exports = TxConfirmationSub;