Revert "Remove unused test data files"

This reverts commit ef24980e667debd0cb8f1f26218c452bacbbe084.
diff --git a/tests/data_files/dir3/Readme b/tests/data_files/dir3/Readme
new file mode 100644
index 0000000..189dadc
--- /dev/null
+++ b/tests/data_files/dir3/Readme
@@ -0,0 +1 @@
+This is just to make sure files that don't parse as certs are ignored.