adding DS_Store to gitignore

Change-Id: I8d73aa015d33bee53e67e64685009236e9b3fe45
diff --git a/.gitignore b/.gitignore
index d4d4e6d..71e25dd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,5 +11,6 @@
 *.pyc
 dependency-reduced-pom.xml
 .idea
+*.DS_Store
 
 core/store/trivial/data/