title: forRoot in Angular libraries not workig , but in appmodule its working as expected
body: <p>When i import a module in appmodule and call forRoot everything is working no Injection problems.
  But when i remove from appmodule and add in a lazyloaded module calling forRoot not working as expected.
  Getting   <strong>NullInjectorError: No provider for InjectionToken forRoot()</strong> , is it mandatory that all modules needs to be imported in appmodule. My main moto is to reduce the main.js bundle size , so don't want to load all modules in appmodule</p>
  <p>Appmodule =&gt; featureModule.forRoot(env) =&gt; working Fine</p>
  <p>LazyloadedModule =&gt; fetaureModule.forRoot(env) =&gt; Null Injector error</p>