feat: add app shell (angular-material)

Add app shell built using angular-material and flex-layout. Refractor
code due to configuration changes.

Fixes #52

src/app/navigation/navigation.component.spec.ts

@@ -1,7 +1,4 @@
-/* tslint:disable:no-unused-variable */
 import { async, ComponentFixture, TestBed } from '@angular/core/testing';
-import { By } from '@angular/platform-browser';
-import { DebugElement } from '@angular/core';
 
 import { NavigationComponent } from './navigation.component';