feat(gzip): Adding gzip support for framework 4.5 or above. (#218)

Author: msohailhussain

OptimizelySDK.Tests/ConfigTest/HttpProjectConfigManagerTest.cs

@@ -18,7 +18,6 @@
 using NUnit.Framework;
 using OptimizelySDK.Config;
 using OptimizelySDK.Logger;
-using OptimizelySDK.Notifications;
 using OptimizelySDK.Tests.NotificationTests;
 using System;
 using System.Diagnostics;
@@ -55,6 +54,13 @@ public void TestHttpConfigManagerRetreiveProjectConfigByURL()
             Assert.NotNull(httpManager.GetConfig());
         }
 
+        [Test]
+        public void TestHttpClientHandler()
+        {
+            var httpConfigHandler = HttpProjectConfigManager.GetHttpClientHandler();
+            Assert.IsTrue(httpConfigHandler.AutomaticDecompression == (System.Net.DecompressionMethods.Deflate | System.Net.DecompressionMethods.GZip));
+        }
+
         [Test]
         public void TestHttpConfigManagerRetreiveProjectConfigGivenEmptyFormatUseDefaultFormat()
         {

OptimizelySDK/Config/HttpProjectConfigManager.cs

@@ -42,9 +42,20 @@ public Task OnReady()
 
 #if !NET40 && !NET35
         private static System.Net.Http.HttpClient Client;
-        static HttpProjectConfigManager() {
-            Client = new System.Net.Http.HttpClient();
+        static HttpProjectConfigManager()
+        {
+            Client = new System.Net.Http.HttpClient(GetHttpClientHandler());
         }
+
+        public static System.Net.Http.HttpClientHandler GetHttpClientHandler()
+        {
+            var handler = new System.Net.Http.HttpClientHandler() {
+                AutomaticDecompression = System.Net.DecompressionMethods.GZip | System.Net.DecompressionMethods.Deflate
+            };
+
+            return handler;
+        }
+
         private string GetRemoteDatafileResponse()
         {
             var request = new System.Net.Http.HttpRequestMessage {