Update zone.js peer dependency #1867

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 5.4.x
• Cross-platform modules: 5.4.2
• Android Runtime: 5.4.0
• iOS Runtime:
• Plugin(s):
• NativeScript-Angular: 8.0.1
• Angular: 8.0.0

Describe the bug

Angular 8+ depends on zone.js@^0.9.1 but nativescript-angular wants zone.js@^0.8.4.

To Reproduce

On a nativescript-angular 8.0.1 project -> Run: npm ls

npm WARN nativescript-angular@8.0.1 requires a peer of zone.js@^0.8.4 but none is installed. You must install peer dependencies yourself.

Expected behavior
No warning about peer dependency.