Add delay to test (#4664)

Author: sigurdm

test/check_resolution_up_to_date_test.dart

@@ -34,6 +34,8 @@ void main() {
       output: contains('Resolution is up-to-date'),
       exitCode: 0,
     );
+
+    // Timestamp resolution is rather poor especially on windows.
     await Future<Null>.delayed(const Duration(seconds: 1));
 
     await d.appDir(dependencies: {'foo': '2.0.0'}).create();
@@ -96,6 +98,9 @@ void main() {
       ),
     ]).create();
 
+    // Timestamp resolution is rather poor especially on windows.
+    await Future<Null>.delayed(const Duration(seconds: 1));
+
     await runPub(
       args: ['check-resolution-up-to-date'],
       environment: {'_PUB_TEST_SDK_VERSION': '3.5.0'},