Add web front-end and fix API issues

node_modules/rxjs/dist/esm5/internal/util/SequenceError.js

@@ -0,0 +1,9 @@
+import { createErrorClass } from './createErrorClass';
+export var SequenceError = createErrorClass(function (_super) {
+    return function SequenceErrorImpl(message) {
+        _super(this);
+        this.name = 'SequenceError';
+        this.message = message;
+    };
+});
+//# sourceMappingURL=SequenceError.js.map