Bump Bazel version to 3.0.0

Change-Id: I81d0c975a2ee54c91555018320d248088492c0c5
diff --git a/jenkins-docker/slave-bazel-nocache/Makefile b/jenkins-docker/slave-bazel-nocache/Makefile
index a858fc4..a61600b 100644
--- a/jenkins-docker/slave-bazel-nocache/Makefile
+++ b/jenkins-docker/slave-bazel-nocache/Makefile
@@ -1,6 +1,6 @@
 NO_CACHE=false
 IMAGE=gerritforge/gerrit-ci-slave-bazel:debian-stretch-nocache
-BAZEL_VER=2.2.0
+BAZEL_VER=3.0.0
 BUILDIFIER_VER=2.2.1
 BAZELISK_VER=1.1.0
 NODE_VER=10