Remove a conflicting definition of runningAsTest.

lib/src/io.dart

Index: lib/src/io.dart
diff --git a/lib/src/io.dart b/lib/src/io.dart
index ff02921f256cbe7558f4b7dc71d6b2012b0496c4..10a08b644c53865078c6323a6ce3f454c21bcc4e 100644
--- a/lib/src/io.dart
+++ b/lib/src/io.dart
@@ -564,7 +564,7 @@ final Stream<String> stdinLines = streamToLines(
 /// should just be a fragment like, "Are you sure you want to proceed".
 Future<bool> confirm(String message) {
   log.fine('Showing confirm message: $message');
-  if (runningAsTest) {
+  if (runningFromTest) {
     log.message("$message (y/n)?");
   } else {
     stdout.write(log.format("$message (y/n)? "));