Add web front-end and fix API issues

node_modules/rxjs/dist/esm5/testing/index.js

@@ -0,0 +1,2 @@
+export { TestScheduler } from '../internal/testing/TestScheduler';
+//# sourceMappingURL=index.js.map

node_modules/rxjs/dist/esm5/testing/index.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"index.js","sourceRoot":"","sources":["../../../src/testing/index.ts"],"names":[],"mappings":"AAAA,OAAO,EAAE,aAAa,EAAc,MAAM,mCAAmC,CAAC"}