Fix BUILD files

cluster/gce/BUILD

@@ -9,7 +9,7 @@ pkg_tar(
         "container-linux/configure-helper.sh",
         "gci/configure-helper.sh",
         "gci/health-monitor.sh",
-        "gci/mounter/mounter",
+        "//cluster/gce/gci/mounter",
     ],
     mode = "0755",
     strip_prefix = ".",

hack/BUILD

@@ -2,6 +2,13 @@ package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])
 
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_binary",
+    "go_library",
+    "go_test",
+)
+
 filegroup(
     name = "package-srcs",
     srcs = glob(["**"]),