go/rules.bzl: update rules_go to 15.3, use gazelle for go_repository

WORKSPACE

@@ -6,20 +6,24 @@ load("//protobuf:rules.bzl", "github_archive")
 # Go support requires rules_go
 # ================================================================
 
-github_archive(
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
     name = "io_bazel_rules_go",
-    commit = "f676870c5caf8df559a51e7aa005d2ece148a03b",  # 0.10.3
-    org = "bazelbuild",
-    repo = "rules_go",
-    sha256 = "d1740b1a75d3c51f1c37e5a42ed032d113bdf1de35c393c609940af491ab6035",
+    urls = ["https://github.com/bazelbuild/rules_go/releases/download/0.15.3/rules_go-0.15.3.tar.gz"],
+    sha256 = "97cf62bdef33519412167fd1e4b0810a318a7c234f5f8dc4f53e2da86241c492",
 )
-
 load("@io_bazel_rules_go//go:def.bzl", "go_rules_dependencies", "go_register_toolchains")
-
 go_rules_dependencies()
-
 go_register_toolchains()
 
+http_archive(
+    name = "bazel_gazelle",
+    urls = ["https://github.com/bazelbuild/bazel-gazelle/releases/download/0.14.0/bazel-gazelle-0.14.0.tar.gz"],
+    sha256 = "c0a5739d12c6d05b6c1ad56f2200cb0b57c5a70e03ebd2f7b87ce88cabf09c7b",
+)
+load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
+gazelle_dependencies()
+
 # ================================================================
 # closure js_proto_library support requires rules_closure
 # ================================================================

go/rules.bzl

@@ -1,4 +1,5 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_repository")
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@bazel_gazelle//:deps.bzl", "go_repository")
 load("//protobuf:rules.bzl", "proto_compile", "proto_repositories")
 load("//go:deps.bzl", "DEPS")