Make LastFm user agent configurable

lib/last_fm/api_impl.ex

@@ -30,7 +30,7 @@ defmodule LastFm.APIImpl do
 
     Logger.debug("Fetching data from #{sanitize_url(url, config.api_key)}")
 
-    case json_get(url) do
+    case json_get(url, config.user_agent) do
       {:ok, response} ->
         {:ok,
          response
@@ -61,7 +61,7 @@ defmodule LastFm.APIImpl do
 
     Logger.debug("Fetching data from #{sanitize_url(url, config.api_key)}")
 
-    case json_get(url) do
+    case json_get(url, config.user_agent) do
       {:ok, response} ->
         {:ok,
          response
@@ -77,11 +77,10 @@ defmodule LastFm.APIImpl do
     end
   end
 
-  defp json_get(url) do
+  defp json_get(url, user_agent) do
     req =
       Finch.build(:get, url, [
-        # TODO: move user agent to config
-        {"User-Agent", "MusicLibrary/0.1.0 ( cloud8421@gmail.com )"}
+        {"User-Agent", user_agent}
       ])
 
     case Finch.request(req, LastFm.Finch, @request_opts) do

lib/last_fm/config.ex

@@ -4,14 +4,16 @@ defmodule LastFm.Config do
           api_key: String.t(),
           user: String.t(),
           auto_refresh: boolean(),
-          refresh_interval: pos_integer()
+          refresh_interval: pos_integer(),
+          user_agent: String.t()
         }
 
   defstruct api: LastFm.Api,
             api_key: "",
             user: "",
             auto_refresh: true,
-            refresh_interval: 60_000
+            refresh_interval: 60_000,
+            user_agent: "change me"
 
   @spec resolve(atom) :: t
   def resolve(otp_app) do