Deprecate c.t.server.AdminHttpServer#routes

Problem

`c.t.server.AdminHttpServer#routes` should have been marked deprecated
some time ago.

Solution

Mark `c.t.server.AdminHttpServer#routes` as deprecated.

Differential Revision: https://phabricator.twitter.biz/D230247

CHANGELOG.rst

@@ -7,6 +7,12 @@ Note that ``PHAB_ID=#`` and ``RB_ID=#`` correspond to associated messages in com
 Unreleased
 ----------
 
+Changes
+~~~~~~~
+
+* Deprecate `c.t.server.AdminHttpServer#routes`. Routes should be added to the `AdminHttpServer`
+  via `c.t.server.AdminHttpServer#addAdminRoutes`. ``PHAB_ID=D230247``
+
 Runtime Behavior Changes
 ~~~~~~~~~~~~~~~~~~~~~~~~
 

server/src/main/scala/com/twitter/server/AdminHttpServer.scala

@@ -180,8 +180,7 @@ trait AdminHttpServer { self: App =>
     addAdminRoutes(Seq(route))
   }
 
-  // TODO: remove routes, have all routes be added via addAdminRoutes
-  // For now these routes will be added to allRoutes in premain
+  @deprecated("Routes should be added via `AdminHttpServer#addAdminRoutes`", "2018-10-17")
   protected def routes: Seq[Route] = Nil
 
   /**