better error handling

rowers/templates/braintreedropin.html

@@ -0,0 +1,25 @@
+<script src="https://js.braintreegateway.com/web/dropin/1.14.1/js/dropin.min.js"></script>
+<script>
+  var form = document.querySelector('#payment-form');
+  var client_token = '{{ client_token }}';
+  braintree.dropin.create({
+    authorization: client_token,
+  container: '#bt-dropin',
+  paypal: {
+      flow: 'vault'
+  }
+  }, function (createErr, instance) {
+    form.addEventListener('submit', function (event) {
+      event.preventDefault();
+      instance.requestPaymentMethod(function (err, payload) {
+        if (err) {
+          console.log('Error', err);
+          return;
+        }
+        // Add the nonce to the form and submit
+        document.querySelector('#nonce').value = payload.nonce;
+        form.submit();
+      });
+    });
+  });
+</script>