Add gh workflow file

.github/workflows/test-helix.yml

@@ -0,0 +1,30 @@
+name: Test (Helix)
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+
+  build:
+
+    runs-on: windows-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+
+    - name: Install .NET
+      uses: actions/setup-dotnet@v3
+      with:
+        dotnet-version: 8.0.x
+
+    - name: Run tests
+      run: |
+          cd .\MiniTwitch.Helix.Test\
+          dotnet test
+