Spring cleaning

* Remove unused subs
* Move cover urls into subscriptios
* Check if TODOs and FIXMEs are still up to date

test/cljs/airsonic_ui/subs_test.cljs

@@ -0,0 +1,16 @@
+(ns airsonic-ui.subs-test
+  (:require [cljs.test :refer [deftest testing is]]
+            [airsonic-ui.fixtures :refer [song]]
+            [airsonic-ui.utils.api :as api]
+            [airsonic-ui.subs :as subs]))
+
+(deftest cover-images
+  (let [credentials {:server "https://foo.bar"
+                     :u "test-user"
+                     :p "some-random-password"}]
+    (testing "Should give the correct path once the credentials are set"
+      (is (= (api/cover-url (:server credentials)
+                            (select-keys credentials [:u :p])
+                            song
+                            48)
+             (subs/cover-url [credentials] [:_ song 48]))))))