More tests for the UpdateChecker class. It should be done for now.

tests/data/index.json

@@ -0,0 +1,9 @@
+{
+	"ApiVersion": 0,
+	"Versions": [
+		{ "Id": 0, "Name": "1.0.0" },
+		{ "Id": 1, "Name": "1.0.1" },
+		{ "Id": 2, "Name": "1.0.2" },
+		{ "Id": 3, "Name": "1.0.3" }
+	]
+}