Outdated fix messages (#2401)

diff --git a/lib/src/command/outdated.dart b/lib/src/command/outdated.dart
index e4108f3..a4d6419 100644
--- a/lib/src/command/outdated.dart
+++ b/lib/src/command/outdated.dart
@@ -231,7 +231,7 @@
     Future<List<_FormattedString>> Function(_PackageDetails) marker,
     {@required bool useColors, @required bool includeDevDependencies}) async {
   if (rows.isEmpty) {
-    log.message('Found no outdated packages');
+    log.message('Found no outdated packages.');
     return;
   }
   final directRows = rows.where((row) => row.kind == _DependencyKind.direct);
diff --git a/test/outdated/goldens/no_dependencies.txt b/test/outdated/goldens/no_dependencies.txt
index 9de1ac4..3d52184 100644
--- a/test/outdated/goldens/no_dependencies.txt
+++ b/test/outdated/goldens/no_dependencies.txt
@@ -6,21 +6,21 @@
 
 $ pub outdated --format=no-color
 Resolving...
-Found no outdated packages
+Found no outdated packages.
 
 $ pub outdated --format=no-color --mark=none
 Resolving...
-Found no outdated packages
+Found no outdated packages.
 
 $ pub outdated --format=no-color --up-to-date
 Resolving...
-Found no outdated packages
+Found no outdated packages.
 
 $ pub outdated --format=no-color --pre-releases
 Resolving...
-Found no outdated packages
+Found no outdated packages.
 
 $ pub outdated --format=no-color --no-dev-dependencies
 Resolving...
-Found no outdated packages
+Found no outdated packages.