Remove leftovers from Buck-based build

Change-Id: I2d42f516aea29c1bc8a49367cdee38c12bc03686

.gitignore

diff --git a/.gitignore b/.gitignore
index d9511b2..499784b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,3 @@
-/.buckversion
-/.buckd
-/.watchmanconfig
-/buck-out
-/bucklets
 /.classpath
 /.project
 /.settings/org.maven.ide.eclipse.prefs