Refactoring updater

1. move into a separate class
2. remove unused nuget package

Wox.Core/Updater.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Diagnostics;
+using System.Net;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using Squirrel;
+using Wox.Core.UserSettings;
+using Wox.Infrastructure.Http;
+using Wox.Infrastructure.Logger;
+
+namespace Wox.Core
+{
+    public static class Updater
+    {
+        [Conditional("RELEASE")]
+        public static async void UpdateApp()
+        {
+            try
+            {
+                // todo 5/9 the return value of UpdateApp() is NULL, fucking useless!
+                using (var updater= await UpdateManager.GitHubUpdateManager(Infrastructure.Wox.Github))
+                {
+                    await updater.UpdateApp();
+                }
+            }
+            catch (WebException ex)
+            {
+                Log.Error(ex);
+            }
+            catch (Exception exception)
+            {
+                const string info = "Update.exe not found, not a Squirrel-installed app?";
+                if (exception.Message == info)
+                {
+                    Log.Warn(info);
+                }
+                else
+                {
+                    throw;
+                }
+            }
+        }
+
+        public static async Task<string> NewVersion()
+        {
+            const string githubAPI = @"https://api.github.com/repos/wox-launcher/wox/releases/latest";
+            var response = await HttpRequest.Get(githubAPI, HttpProxy.Instance);
+
+            if (!string.IsNullOrEmpty(response))
+            {
+                JContainer json;
+                try
+                {
+                    json = (JContainer)JsonConvert.DeserializeObject(response);
+                }
+                catch (JsonSerializationException e)
+                {
+                    Log.Error(e);
+                    return string.Empty;
+                }
+                var version = json?["tag_name"]?.ToString();
+                if (!string.IsNullOrEmpty(version))
+                {
+                    return version;
+                }
+                else
+                {
+                    Log.Warn("Can't find tag_name from Github API response");
+                    return string.Empty;
+                }
+            }
+            else
+            {
+                Log.Warn("Can't get response from Github API");
+                return string.Empty;
+            }
+        }
+
+        public static int NumericVersion(string version)
+        {
+            var newVersion = version.Replace("v", ".").Replace(".", "").Replace("*", "");
+            return int.Parse(newVersion);
+        }
+    }
+}