Updated the files.

my-app/node_modules/@angular-devkit/architect/testing/test-project-host.d.ts

@@ -0,0 +1,35 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+/// <reference types="node" />
+/// <reference types="@types/node/fs" />
+/// <reference types="@types/node/ts4.8/fs" />
+import { Path, PathFragment, virtualFs } from '@angular-devkit/core';
+import { NodeJsSyncHost } from '@angular-devkit/core/node';
+import { Stats } from 'fs';
+import { Observable } from 'rxjs';
+/**
+ * @deprecated
+ */
+export declare class TestProjectHost extends NodeJsSyncHost {
+    protected _templateRoot: Path;
+    private _currentRoot;
+    private _scopedSyncHost;
+    constructor(_templateRoot: Path);
+    root(): Path;
+    scopedSync(): virtualFs.SyncDelegateHost<Stats>;
+    initialize(): Observable<void>;
+    restore(): Observable<void>;
+    writeMultipleFiles(files: {
+        [path: string]: string | ArrayBufferLike | Buffer;
+    }): void;
+    replaceInFile(path: string, match: RegExp | string, replacement: string): void;
+    appendToFile(path: string, str: string): void;
+    fileMatchExists(dir: string, regex: RegExp): PathFragment | undefined;
+    copyFile(from: string, to: string): void;
+    private findUniqueFolderPath;
+}