add testing environment

app/views/shared/_test_mode_toggle.html.erb

@@ -0,0 +1,10 @@
+<% if can?(:manage, EncryptedConfig) || (current_user != true_user && current_account.testing?) %>
+  <%= form_for '', url: testing_account_path, method: current_account.testing? ? :delete : :get, html: { class: 'flex' } do |f| %>
+    <label class="flex items-center justify-between py-2.5" for="testing_toggle">
+      <span class="mr-2 text-lg">
+        Test Environment
+      </span>
+      <%= f.check_box :testing_toggle, class: 'toggle', checked: current_account.testing?, onchange: 'this.form.requestSubmit()' %>
+    </label>
+  <% end %>
+<% end %>