Add .buckd to .gitignore

Change-Id: I2f8a060e123c29c06b5e2f4e347b42212ec4358b

.gitignore

diff --git a/.gitignore b/.gitignore
index 5c784fe..cd7c29f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 /.settings
 /buck-out
 /gitiles.config
+/.buckd