Added rudimentary base test for the Cdn Helper

Author: MeixDev

test/discord_api_test.dart

@@ -1,12 +1,18 @@
+import 'package:discord_api/src/discord_cdn_helper.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'package:discord_api/discord_api.dart';
-
 void main() {
-  test('adds one to input values', () {
-    final calculator = Calculator();
-    expect(calculator.addOne(2), 3);
-    expect(calculator.addOne(-7), -6);
-    expect(calculator.addOne(0), 1);
+  final cdn = DiscordCdnHelper.instance;
+
+  group('DiscordCdnHelper tests', () {
+    test("Get 131492741409538048's Avatar in size 64", () {
+      final value = cdn.getUserAvatar(
+          userId: "131492741409538048",
+          userAvatarHash: "64d4f5dfcb00059794c20f656cb19c2b",
+          size: 64);
+      expect(value, isNotNull);
+      expect(value,
+          "https://cdn.discordapp.com/avatars/131492741409538048/64d4f5dfcb00059794c20f656cb19c2b.png?size=64");
+    });
   });
 }