Removed old rules from eslint

Tried hand at testing by fixing the spec files with import. However, still many errors and given up now.

overlord/src/app/purchase/purchase-dialog.component.spec.ts

@@ -1,4 +1,5 @@
 import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+import { MatDialogModule } from '@angular/material/dialog';
 
 import { PurchaseDialogComponent } from './purchase-dialog.component';
 
@@ -8,7 +9,7 @@ describe('PurchaseDialogComponent', () => {
 
   beforeEach(async(() => {
     TestBed.configureTestingModule({
-      declarations: [PurchaseDialogComponent],
+      declarations: [MatDialogModule, PurchaseDialogComponent],
     }).compileComponents();
   }));