Add web front-end and fix API issues

node_modules/rxjs/dist/esm5/internal/operators/last.js

@@ -0,0 +1,13 @@
+import { EmptyError } from '../util/EmptyError';
+import { filter } from './filter';
+import { takeLast } from './takeLast';
+import { throwIfEmpty } from './throwIfEmpty';
+import { defaultIfEmpty } from './defaultIfEmpty';
+import { identity } from '../util/identity';
+export function last(predicate, defaultValue) {
+    var hasDefaultValue = arguments.length >= 2;
+    return function (source) {
+        return source.pipe(predicate ? filter(function (v, i) { return predicate(v, i, source); }) : identity, takeLast(1), hasDefaultValue ? defaultIfEmpty(defaultValue) : throwIfEmpty(function () { return new EmptyError(); }));
+    };
+}
+//# sourceMappingURL=last.js.map