Use the same observer_cli copy for both erlang and rabbitmq_cli

Author: HoloRin

deps/rabbitmq_cli/BUILD.bazel

@@ -20,6 +20,7 @@ rabbitmqctl(
     visibility = ["//visibility:public"],
     deps = [
         "//deps/rabbit_common:erlang_app",
+        "@observer_cli//:erlang_app",
         "@stdout_formatter//:erlang_app",
     ],
 )
@@ -120,6 +121,7 @@ rabbitmqctl_test(
         "//deps/amqp_client:erlang_app",
         "//deps/rabbit:erlang_app",
         "//deps/rabbit_common:erlang_app",
+        "@observer_cli//:erlang_app",
         "@stdout_formatter//:erlang_app",
     ],
 )

deps/rabbitmq_cli/mix.exs

@@ -145,7 +145,11 @@ defmodule RabbitMQCtl.MixfileBase do
         path: external_dep_path("stdout_formatter"),
         compile: if(is_bazel, do: false, else: make_cmd),
       },
-      {:observer_cli, "1.7.4"},
+      {
+        :observer_cli,
+        path: external_dep_path("observer_cli"),
+        compile: if(is_bazel, do: false, else: make_cmd),
+      },
       {:amqp, "~> 2.1.0", only: :test},
       {:dialyxir, "~> 0.5", only: :test, runtime: false},
       {:temp, "~> 0.4", only: :test},