Move placeholder file to a .gitignore

Change-Id: I605147f1428aa5b2c4948dc66afe25da1691099d
diff --git a/TestON/logs/.gitignore b/TestON/logs/.gitignore
new file mode 100644
index 0000000..5e7d273
--- /dev/null
+++ b/TestON/logs/.gitignore
@@ -0,0 +1,4 @@
+# Ignore everything in this directory
+*
+# Except this file
+!.gitignore