Remove BUCK build file

Change-Id: Ia49be1fd803e5d8ead6b633641ec44252074d4e2

BUCK

diff --git a/BUCK b/BUCK
deleted file mode 100644
index 1606b51..0000000
--- a/BUCK
+++ /dev/null
@@ -1,5 +0,0 @@
-gerrit_plugin(
-  name = 'avatars-gravatar',
-  srcs = glob(['src/main/java/**/*.java']),
-  resources = glob(['src/main/resources/**/*']),
-)