Use kamal network for containers

Create a `kamal` network for the proxy and app containers to run in.
This allows the proxy to refer to the app containers by name.

test/integration/app_test.rb

@@ -4,13 +4,15 @@ class IntegrationAppTest < IntegrationTest
   test "stop, start, boot, logs, images, containers, exec, remove" do
     kamal :envify
 
+    kamal :setup
+
     kamal :deploy
 
     assert_app_is_up
 
     kamal :app, :stop
 
-    assert_app_is_down
+    assert_app_is_down response_code: "502"
 
     kamal :app, :start
 
@@ -50,6 +52,6 @@ class IntegrationAppTest < IntegrationTest
 
     kamal :app, :remove
 
-    assert_app_is_down
+    assert_app_is_down response_code: "502"
   end
 end

test/integration/integration_test.rb

@@ -46,8 +46,8 @@ class IntegrationTest < ActiveSupport::TestCase
 
     def assert_app_is_down(response_code: "503")
       response = app_response
-      debug_response_code(response, "503")
-      assert_equal "503", response.code
+      debug_response_code(response, response_code)
+      assert_equal response_code, response.code
     end
 
     def assert_app_is_up(version: nil)

test/integration/main_test.rb

@@ -2,6 +2,7 @@ require_relative "integration_test"
 
 class IntegrationMainTest < IntegrationTest
   test "envify, deploy, redeploy, rollback, details and audit" do
+    kamal :server, :bootstrap
     kamal :envify
     assert_local_env_file "SECRET_TOKEN=1234"
     assert_remote_env_file "SECRET_TOKEN=1234"

test/integration/proxy_test.rb

@@ -2,6 +2,7 @@ require_relative "integration_test"
 
 class IntegrationProxyTest < IntegrationTest
   test "boot, reboot, stop, start, restart, logs, remove" do
+    kamal :server, :bootstrap
     kamal :envify
 
     kamal :proxy, :boot