More aggressive build ignores

Summary:
This strips another 8MB from our node_modules.

Checked out the largest individual files in with Disk Inventory X.

{F238464588}

Reviewed By: nikoant

Differential Revision: D21765847

fbshipit-source-id: d74b0eae270b86f0518d7e73288fd773b24535da

desktop/scripts/copy-package-with-dependencies.ts

@@ -17,6 +17,9 @@ const DEFAULT_BUILD_IGNORES = [
   'LICENSE*',
   '*.ts',
   '*.ls',
+  '*.flow',
+  '*.tsbuildinfo',
+  '*.map',
   'Gruntfile*',
 ];