Add /tests/ to CODEOWNERS

Signed-off-by: Brenden Blanco <bblanco@gmail.com>
diff --git a/CODEOWNERS b/CODEOWNERS
index 3c1476c..a009420 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -20,3 +20,6 @@
 
 # Python API
 /src/python/ @drzaeus77 @goldshtn
+
+# Tests
+/tests/ @drzaeus77 @yonghong-song