Add CI

.github/workflows/build-test.yml

@@ -0,0 +1,21 @@
+name: Build & Test
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies
+        run: dotnet restore
+      - name: Build
+        run: dotnet build --configuration Release --no-restore
+      # - name: Test
+      #   run: dotnet test --no-restore --verbosity normal