Add docker upgrade link to admin page.

.gitignore

@@ -0,0 +1,2 @@
+*.swp
+

assets/javascripts/upgrade-header.js.handlebars

@@ -0,0 +1,3 @@
+<tr>
+  <th colspan="5">{{i18n docker.upgrade}} <a href="/admin/docker" target="_blank">{{i18n docker.perform_upgrade}}</a></th>
+</tr>

config/locales/client.en.yml

@@ -0,0 +1,5 @@
+en:
+  js:
+    docker:
+      upgrade: "Upgrades are performed by Docker."
+      perform_upgrade: "Click here to upgrade."

plugin.rb

@@ -13,8 +13,9 @@ end
 Rails.configuration.assets.precompile += ['docker_manager.js']
 
 after_initialize do
-
   Discourse::Application.routes.append do
     mount ::DockerManager::Engine, at: "/"
   end
 end
+
+register_asset "javascripts/upgrade-header.js.handlebars"