create test project and basic model loading tests

gpt4all-bindings/csharp/Gpt4All.Tests/ModelFactoryTests.cs

@@ -0,0 +1,31 @@
+using Xunit;
+
+namespace Gpt4All.Tests;
+
+public class ModelFactoryTests
+{
+    private readonly Gpt4AllModelFactory _modelFactory;
+
+    public ModelFactoryTests()
+    {
+        _modelFactory = new Gpt4AllModelFactory();
+    }
+
+    [Fact]
+    public void CanLoadLlamaModel()
+    {
+        using var model = _modelFactory.LoadLlamaModel(Constants.LLAMA_MODEL_PATH);
+    }
+
+    [Fact]
+    public void CanLoadGptjModel()
+    {
+        using var model = _modelFactory.LoadGptjModel(Constants.GPTJ_MODEL_PATH);
+    }
+
+    [Fact]
+    public void CanLoadMptModel()
+    {
+        using var model = _modelFactory.LoadMptModel(Constants.MPT_MODEL_PATH);
+    }
+}