Add trailing comma

pre_commit_hooks/detect_private_key.py

diff --git a/pre_commit_hooks/detect_private_key.py b/pre_commit_hooks/detect_private_key.py
index 0c2eca4..d187364 100644
--- a/pre_commit_hooks/detect_private_key.py
+++ b/pre_commit_hooks/detect_private_key.py
@@ -7,7 +7,7 @@
     b'BEGIN RSA PRIVATE KEY',
     b'BEGIN DSA PRIVATE KEY',
     b'BEGIN EC PRIVATE KEY',
-    b'BEGIN OPENSSH PRIVATE KEY'
+    b'BEGIN OPENSSH PRIVATE KEY',
 ]