fix(core): resolve lint issues

npm/ng-packs/packages/core/src/lib/strategies/loading.strategy.ts

@@ -15,10 +15,10 @@ export abstract class LoadingStrategy<T extends HTMLScriptElement | HTMLLinkElem
 
   abstract createElement(): T;
 
-  createStream<T extends Event>(): Observable<T> {
+  createStream<E extends Event>(): Observable<E> {
     return of(null).pipe(
       switchMap(() =>
-        fromLazyLoad<T>(
+        fromLazyLoad<E>(
           this.createElement(),
           this.domStrategy,
           this.crossOriginStrategy,

npm/ng-packs/packages/core/src/lib/tests/dom.strategy.spec.ts

@@ -29,7 +29,7 @@ describe('DomStrategy', () => {
 });
 
 describe('DOM_STRATEGY', () => {
-  let div = document.createElement('DIV');
+  const div = document.createElement('DIV');
 
   beforeEach(() => {
     document.body.innerHTML = '';

npm/ng-packs/packages/core/src/lib/utils/lazy-load-utils.ts

@@ -16,8 +16,8 @@ export function fromLazyLoad<T extends Event>(
   contentSecurityStrategy.applyCSP(element);
   domStrategy.insertElement(element);
 
-  return Observable.create((observer: Observer<Event>) => {
-    element.onload = event => {
+  return new Observable((observer: Observer<T>) => {
+    element.onload = (event: T) => {
       clearCallbacks(element);
       observer.next(event);
       observer.complete();
@@ -39,6 +39,7 @@ export function fromLazyLoad<T extends Event>(
 }
 
 function createErrorHandler(observer: Observer<Event>, element: HTMLElement) {
+  /* tslint:disable-next-line:only-arrow-functions */
   return function(event: Event | string) {
     clearCallbacks(element);
     element.parentNode.removeChild(element);