Tests now pass with local authentication

This is the first step of a multi-step SaaS engine extraction.

Looking ahead to an open source release, we need to make sure that
local authentication is treated as an "official" option, and not just
a hack I added for Kevin to do load testing outside our DC. So this PR
gets to green, and adds a CI step in "local authentication" mode.

This all probably feels a little hacky to you, Reader, but the goal of
this change is to ease the next step, which will be extracting the
37id and Queenbee integrations into a proprietary "SaaS mode" engine.

In service of that goal, this commit simply wraps all of the dependent
code and tests with a conditional check on
`config.x.local_authentication`.

test/controllers/controller_authentication_test.rb

@@ -1,36 +1,34 @@
 require "test_helper"
 
 class ControllerAuthenticationTest < ActionDispatch::IntegrationTest
-  test "access without an account slug redirects to launchpad" do
-    integration_session.default_url_options[:script_name] = "" # no tenant
+  if Rails.application.config.x.local_authentication
+    test "access without an account slug redirects to new session" do
+      integration_session.default_url_options[:script_name] = "" # no tenant
 
-    get cards_path
-
-    assert_redirected_to Launchpad.login_url(product: true)
-  end
-
-  test "access with an account slug but no session redirects to launchpad" do
-    get cards_path
-
-    assert_redirected_to Launchpad.login_url(product: true, account: Account.sole)
-  end
-
-  test "local auth, access without an account slug redirects to launchpad" do
-    integration_session.default_url_options[:script_name] = "" # no tenant
-
-    with_local_auth do
       get cards_path
+
+      assert_redirected_to new_session_path
     end
 
-    assert_redirected_to Launchpad.login_url(product: true)
-  end
-
-  test "local auth, access with an account slug but no session redirects to new session" do
-    with_local_auth do
+    test "access with an account slug but no session redirects to new session" do
       get cards_path
+
+      assert_redirected_to new_session_path
+    end
+  else
+    test "access without an account slug redirects to launchpad" do
+      integration_session.default_url_options[:script_name] = "" # no tenant
+
+      get cards_path
+
+      assert_redirected_to Launchpad.login_url(product: true)
     end
 
-    assert_redirected_to new_session_path
+    test "access with an account slug but no session redirects to launchpad" do
+      get cards_path
+
+      assert_redirected_to Launchpad.login_url(product: true, account: Account.sole)
+    end
   end
 
   test "access with an account slug and a session allows functional access" do