feat(schematics): create facade skeleton when creating an extension

Closes #109

schematics/src/extension/factory_spec.ts

@@ -28,7 +28,7 @@ describe('Extension Schematic', () => {
       .toPromise();
   });
 
-  it('should create a page in root by default', async () => {
+  it('should create an extension', async () => {
     const options = { ...defaultOptions };
 
     const tree = await schematicRunner.runSchematicAsync('extension', options, appTree).toPromise();
@@ -37,6 +37,7 @@ describe('Extension Schematic', () => {
       Array [
         "/projects/bar/src/app/extensions/foo/foo.module.ts",
         "/projects/bar/src/app/extensions/foo/exports/foo-exports.module.ts",
+        "/projects/bar/src/app/extensions/foo/facades/foo.facade.ts",
         "/projects/bar/src/app/extensions/foo/pages/foo-routing.module.ts",
         "/projects/bar/src/app/extensions/foo/store/foo-store.ts",
         "/projects/bar/src/app/extensions/foo/store/foo-store.module.ts",

schematics/src/extension/files/__name@dasherize__/facades/__name@dasherize__.facade.__tsext__

@@ -0,0 +1,13 @@
+import { Injectable } from '@angular/core';
+import { Store, select } from '@ngrx/store';
+
+import { get<%= classify(name) %>State } from '../store/<%= dasherize(name) %>-store';
+
+// tslint:disable:member-ordering
+@Injectable({ providedIn: 'root' })
+export class <%= classify(name) %>Facade {
+  constructor(private store: Store<{}>) {}
+
+  // example for debugging
+  <%= camelize(name) %>State$ = this.store.pipe(select(get<%= classify(name) %>State));
+}