Demo that needs a Gazelle run to happen

If you upgrade the Gazelle dependency, this repo will need a small
change in /demo/BUILD.bazel to use `go_deployable` instead of the
standard `go_binary` which is defined in tools/go/def.bzl (as a wrapper
of go_binary.

BUILD.bazel

@@ -0,0 +1,4 @@
+load("@bazel_gazelle//:def.bzl", "gazelle")
+
+# gazelle:prefix github.com/achew22/renovatedemo
+gazelle(name = "gazelle")

WORKSPACE

@@ -0,0 +1,23 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "io_bazel_rules_go",
+    sha256 = "6776d68ebb897625dead17ae510eac3d5f6342367327875210df44dbe2aeeb19",
+    urls = ["https://github.com/bazelbuild/rules_go/releases/download/0.17.1/rules_go-0.17.1.tar.gz"],
+)
+
+http_archive(
+    name = "bazel_gazelle",
+    sha256 = "7949fc6cc17b5b191103e97481cf8889217263acf52e00b560683413af204fcb",
+    urls = ["https://github.com/bazelbuild/bazel-gazelle/releases/download/0.16.0/bazel-gazelle-0.16.0.tar.gz"],
+)
+
+load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies", "go_register_toolchains")
+
+go_rules_dependencies()
+
+go_register_toolchains()
+
+load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
+
+gazelle_dependencies()

demo/BUILD.bazel

@@ -0,0 +1,10 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+# gazelle:map_kind go_binary go_deployable //tools/go:def.bzl
+
+go_library(
+    name = "go_default_library",
+    srcs = ["demo.go"],
+    importpath = "github.com/achew22/renovatedemo/demo",
+    visibility = ["//visibility:private"],
+)

demo/demo.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Printf("Hello world")
+}

tools/go/def.bzl

@@ -0,0 +1,5 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary")
+
+def go_deployable(**kwargs):
+    print("Wrapped go_binary")
+    go_binary(**kwargs)