Extend BIP174 PSBT base class

src/psbt.js

@@ -0,0 +1,9 @@
+'use strict';
+Object.defineProperty(exports, '__esModule', { value: true });
+const bip174_1 = require('bip174');
+class Psbt extends bip174_1.Psbt {
+  constructor() {
+    super();
+  }
+}
+exports.Psbt = Psbt;