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/clients/create-client/create-client.component.ts

@@ -1,8 +1,7 @@
 import { Component, OnInit} from '@angular/core';
-import { HeaderComponent } from '../../core/shell/header/header.component';
 
 @Component({
-  selector: 'app-create-client',
+  selector: 'mifosx-create-client',
   templateUrl: './create-client.component.html',
   styleUrls: ['./create-client.component.scss']
 })
@@ -12,4 +11,5 @@ export class CreateClientComponent implements OnInit {
 
   ngOnInit() {
   }
+
 }