Instead of rewriting the API call, use ember to rewrite the URL

We now essentially do 2 redirects if you hit a `folder/`

1. If you visit `/ui/dc1/kv/folder/`, `consul` will redirect you to `/ui/dc1/kv/folder`
2. Once redirected to `/ui/dc1/kv/folder` via a 301, use ember/history
API to redirect you back to `/ui/dc1/kv/folder/`.

Bit long winded, but achieves what we want without having to get stuck
into `consul` itself to remove the 301 for the UI

ui-v2/app/routes/dc/kv/index.js

@@ -13,13 +13,17 @@ export default Route.extend(WithKvActions, {
     },
   },
   repo: service('kv'),
-  model: function(params) {
-    let key = params.key || '/';
+  beforeModel: function() {
     // we are index or folder, so if the key doesn't have a trailing slash
     // add one to force a fake findBySlug
+    const params = this.paramsFor(this.routeName);
+    const key = params.key || '/';
     if (!isFolder(key)) {
-      key = key + '/';
+      return this.replaceWith(this.routeName, key + '/');
     }
+  },
+  model: function(params) {
+    let key = params.key || '/';
     const dc = this.modelFor('dc').dc.Name;
     const repo = get(this, 'repo');
     return hash({

ui-v2/tests/acceptance/dc/kvs/trailing-slash.feature

@@ -8,7 +8,7 @@ Feature: dc / kvs / trailing slash
       dc: datacenter
       kv: foo/bar
     ---
-    Then the url should be /datacenter/kv/foo/bar
+    Then the url should be /datacenter/kv/foo/bar/
     And the last GET request was made to "/v1/kv/foo/bar/?keys&dc=datacenter&separator=%2F"
     When I visit the kvs page for yaml
     ---