Fix warning about preferred_cli_env

Author: solnic

mix.exs

@@ -22,10 +22,6 @@ defmodule Sentry.Mixfile do
         plt_add_apps: [:mix, :ex_unit]
       ],
       test_coverage: [tool: ExCoveralls],
-      preferred_cli_env: [
-        "coveralls.html": :test,
-        "test.integrations": :test
-      ],
       name: "Sentry",
       docs: [
         extra_section: "Guides",
@@ -84,6 +80,10 @@ defmodule Sentry.Mixfile do
     ]
   end
 
+  def cli do
+    [preferred_envs: ["coveralls.html": :test, "test.integrations": :test]]
+  end
+
   defp extra_applications(:test), do: [:logger, :opentelemetry]
   defp extra_applications(_other), do: [:logger]