(maint) pdb-core-routes: return a GET for /, not a bare handler fn

Return a compojure GET route for "/" rather than a context wrapping a
plain clojure function.  Before this change the "/" context handler
was being selected for all routes, so all routes returned the
dashboard redirection.  This was likely caused by the recent
clj-parent upgrade that pulled compojure to a much newer version.

cf.
  https://github.com/weavejester/compojure/wiki/Nesting-routes
  6416f22

src/puppetlabs/puppetdb/pdb_routing.clj

@@ -28,33 +28,20 @@
       {:status 503
        :body (tru "PuppetDB is currently down. Try again later.")})))
 
-(defn wrap-with-context [uri route]
-  (compojure/context uri [] route))
-
-(defn pdb-core-routes [defaulted-config get-shared-globals enqueue-command-fn
-                       query-fn clean-fn delete-node-fn]
-  (let [db-cfg #(select-keys (get-shared-globals) [:scf-read-db])]
-    (map #(apply wrap-with-context %)
-         (partition
-          2
-          ;; The remaining get-shared-globals args are for wrap-with-globals.
-          ["/" (fn [req]
-                 (->> req
-                      rreq/request-url
-                      (format "%s/dashboard/index.html")
-                      rr/redirect))
-           "/dashboard" (dashboard/build-app dashboard/default-meter-defs)
-           "/meta" (meta/build-app db-cfg defaulted-config)
-           "/cmd" (cmd/command-app get-shared-globals
-                                   enqueue-command-fn
-                                   (conf/reject-large-commands? defaulted-config)
-                                   (conf/max-command-size defaulted-config))
-           "/query" (server/build-app get-shared-globals)
-           "/admin" (admin/build-app enqueue-command-fn
-                                     query-fn
-                                     db-cfg
-                                     clean-fn
-                                     delete-node-fn)]))))
+(defn pdb-core-routes
+  [defaulted-config get-shared-globals enqueue-command-fn query-fn clean-fn delete-node-fn]
+  (let [db-cfg #(select-keys (get-shared-globals) [:scf-read-db])
+        context #(compojure/context %1 [] %2)]
+    [(compojure/GET "/" req
+       (rr/redirect (str (rreq/request-url req) "/dashboard/index.html")))
+     (context "/dashboard" (dashboard/build-app dashboard/default-meter-defs))
+     (context "/meta" (meta/build-app db-cfg defaulted-config))
+     (context "/cmd" (cmd/command-app get-shared-globals enqueue-command-fn
+                                      (conf/reject-large-commands? defaulted-config)
+                                      (conf/max-command-size defaulted-config)))
+     (context "/query" (server/build-app get-shared-globals))
+     (context "/admin" (admin/build-app enqueue-command-fn query-fn db-cfg clean-fn
+                                        delete-node-fn))]))
 
 (defn pdb-app [root maint-mode-fn app-routes]
   (compojure/context root []