Add an abstraction for http calls

Geekbot.net/Lib/HttpAbstractions.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+
+namespace Geekbot.net.Lib
+{
+    public class HttpAbstractions
+    {
+        public static async Task<T> Get<T>(Uri location, Dictionary<string, string> additionalHeaders = null)
+        {
+            using var client = new HttpClient
+            {
+                BaseAddress = location,
+                DefaultRequestHeaders =
+                {
+                    Accept =
+                    {
+                        MediaTypeWithQualityHeaderValue.Parse("application/json")
+                    }
+                }
+            };
+
+            if (additionalHeaders != null)
+            {
+                foreach (var (name, val) in additionalHeaders)
+                {
+                    client.DefaultRequestHeaders.TryAddWithoutValidation(name, val);
+                }
+            }
+            
+            var response = await client.GetAsync(location.PathAndQuery);
+            response.EnsureSuccessStatusCode();
+            
+            var stringResponse = await response.Content.ReadAsStringAsync();
+            return JsonConvert.DeserializeObject<T>(stringResponse);
+        }
+    }
+}