go: re-do the entire thing

This is a mega-change, but attempting to split this up further is
probably not worth the effort.

Summary:

1. Bump up bazel, rules_go, and others.
2. Switch to new go target naming (bye bye go_default_library)
3. Move go deps to go.mod/go.sum, use make gazelle generate from that
4. Bump up Python deps a bit

And also whatever was required to actually get things to work - loads of
small useless changes.

Tested to work on NixOS and Ubuntu 20.04:

   $ bazel build //...
   $ bazel test //...

Change-Id: I8364bdaa1406b9ae4d0385a6b607f3e7989f98a9
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1583
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/cluster/identd/BUILD.bazel b/cluster/identd/BUILD.bazel
index c49293f..689b922 100644
--- a/cluster/identd/BUILD.bazel
+++ b/cluster/identd/BUILD.bazel
@@ -2,46 +2,46 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_library(
-    name = "go_default_library",
+    name = "identd_lib",
     srcs = ["main.go"],
     importpath = "code.hackerspace.pl/hscloud/cluster/identd",
     visibility = ["//visibility:private"],
     deps = [
-        "//cluster/identd/ident:go_default_library",
-        "//cluster/identd/kubenat:go_default_library",
-        "//go/mirko:go_default_library",
-        "@com_github_golang_glog//:go_default_library",
-        "@io_k8s_apimachinery//pkg/apis/meta/v1:go_default_library",
+        "//cluster/identd/ident",
+        "//cluster/identd/kubenat",
+        "//go/mirko",
+        "@com_github_golang_glog//:glog",
+        "@io_k8s_apimachinery//pkg/apis/meta/v1:meta",
     ],
 )
 
 go_binary(
     name = "identd",
-    embed = [":go_default_library"],
+    embed = [":identd_lib"],
     visibility = ["//visibility:public"],
 )
 
 container_layer(
     name = "layer_bin",
+    directory = "/cluster/identd/",
     files = [
         ":identd",
     ],
-    directory = "/cluster/identd/",
 )
 
 container_image(
     name = "runtime",
     base = "@prodimage-bionic//image",
+    entrypoint = "/cluster/identd/identd",
     layers = [
         ":layer_bin",
     ],
-    entrypoint = "/cluster/identd/identd",
 )
 
 container_push(
     name = "push",
-    image = ":runtime",
     format = "Docker",
+    image = ":runtime",
     registry = "registry.k0.hswaw.net",
     repository = "q3k/identd",
     tag = "{BUILD_TIMESTAMP}-{STABLE_GIT_COMMIT}",