Do not warn about packages without lib dir while pub get. (http://dartbug.com/16515)

sdk/lib/_internal/pub/lib/src/io.dart

Index: sdk/lib/_internal/pub/lib/src/io.dart
diff --git a/sdk/lib/_internal/pub/lib/src/io.dart b/sdk/lib/_internal/pub/lib/src/io.dart
index 085a56104d232f2f9842cb427f571a8cfa880e36..139c33127029adb8c946770362f5e549164edd9e 100644
--- a/sdk/lib/_internal/pub/lib/src/io.dart
+++ b/sdk/lib/_internal/pub/lib/src/io.dart
@@ -393,19 +393,11 @@ void createPackageSymlink(String name, String target, String symlink,
     {bool isSelfLink: false, bool relative: false}) {
   // See if the package has a "lib" directory.
   target = path.join(target, 'lib');
-  log.fine("Creating ${isSelfLink ? "self" : ""}link for package '$name'.");
   if (dirExists(target)) {
+    log.fine("Creating ${isSelfLink ? "self" : ""}link for package '$name'.");
     createSymlink(target, symlink, relative: relative);
     return;
   }
-
-  // It's OK for the self link (i.e. the root package) to not have a lib
-  // directory since it may just be a leaf application that only has
-  // code in bin or web.
-  if (!isSelfLink) {
-    log.warning('Warning: Package $name does not have a "lib" directory so '
-                'you will not be able to import any libraries from it.');
-  }
 }
 
 /// Whether pub is running from within the Dart SDK, as opposed to from the Dart