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

• CLI: 5.0.0
• Node.js: 9.5.0

Describe the bug
Aftertns run android/ios --bundle and on a Vanilla JS hello world application and pasting main-page.css file with some style in it the file is not detected and no webpack build is triggered. This happens on Mac or Windows

To Reproduce

1. Create a new Vanilla JS tabs application
2. Install nativescript-dev-webpack
3. Runtns run android/ios --bundle
4. Create a file outside of the current application named home-items-page.css with the following content:

Label {color: red;}

5. Copy the file in finder (or Windows explorer) and paste the file inside theapp/home folder.

After you paste the file no webpack build is triggered.

Expected behavior
The webpack should be triggered and the items in the list should become red.

Additional context
The issues might be only when using finder as copying through VS Code or command line triggers the webpack build. It's interesting that pasting a file in theapp/ folder restarts the webpack build, but in the subfolders not. And pasting a file with different name (not -page.css) works as well.