Update .gitignore

- exclude buck plugin binary
- exclude watchman config

Change-Id: I2f2251f1833466b6dd66f8a23bcc115558330c31
diff --git a/.gitignore b/.gitignore
index b300f46..5817b7d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,8 @@
 buck-out
 .buckconfig.local
 .buckjavaargs*
+bucklets/plugins/
+.watchmanconfig
 
 /bin/