fix linting issues

src/app/core/utilities/equatable.spec.ts

@@ -14,6 +14,7 @@ class Dog extends EquatableObject<Dog> {
   public favouriteToy: { name: string, colour: string };
 }
 
+// tslint:disable-next-line:max-classes-per-file
 class Owner extends EquatableObject<Owner> {
   @excludeFromEquals
   favouriteFood: string;
@@ -110,4 +111,3 @@ describe('equatable', () => {
     expect(isEqual).toBe(false);
   });
 });
-