Upgrade buildifier to 1.0.0 in docker image

Change-Id: I2f1fc099f38fb844d40185d36270de67139d1e76
diff --git a/jenkins-docker/slave-bazel-nocache/Makefile b/jenkins-docker/slave-bazel-nocache/Makefile
index 2bc47b3..a88a5cb 100644
--- a/jenkins-docker/slave-bazel-nocache/Makefile
+++ b/jenkins-docker/slave-bazel-nocache/Makefile
@@ -1,7 +1,7 @@
 NO_CACHE=false
 IMAGE=gerritforge/gerrit-ci-slave-bazel:debian-stretch-nocache
 BAZEL_VER=2.2.0
-BUILDIFIER_VER=0.29.0
+BUILDIFIER_VER=1.0.0
 BAZELISK_VER=1.1.0
 NODE_VER=10
 WCT_VER=6.8.0