Fixes for bazel version 0.20

Change-Id: Id40ca9c5ee939d462953570d7e59311cbc678708
diff --git a/WORKSPACE b/WORKSPACE
index dc16834..671b958 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -101,13 +101,13 @@
 # See https://github.com/bazelbuild/rules_go for the up to date setup instructions.
 http_archive(
     name = "io_bazel_rules_go",
-    url = "https://github.com/bazelbuild/rules_go/releases/download/0.14.0/rules_go-0.14.0.tar.gz",
+    url = "https://github.com/bazelbuild/rules_go/releases/download/0.16.3/rules_go-0.16.3.tar.gz",
 )
 
 http_archive(
     name = "com_github_bazelbuild_buildtools",
-    strip_prefix = "buildtools-a90c3a9f00e27973d3e759d17f2e2e7d9702d91b",
-    url = "https://github.com/bazelbuild/buildtools/archive/a90c3a9f00e27973d3e759d17f2e2e7d9702d91b.zip",
+    strip_prefix = "buildtools-db073457c5a56d810e46efc18bb93a4fd7aa7b5e",
+    url = "https://github.com/bazelbuild/buildtools/archive/db073457c5a56d810e46efc18bb93a4fd7aa7b5e.zip",
 )
 
 load("@io_bazel_rules_go//go:def.bzl", "go_register_toolchains", "go_rules_dependencies")