Add GitHub Actions configuration (#201)

* new build system based on NUKE build
* support test running on Linux

.github/workflows/ci.yml

@@ -0,0 +1,41 @@
+name: ci
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - 'doc/**'
+      - '*.md'
+
+  pull_request:
+    branches:
+      - main
+    paths-ignore:
+      - 'doc/**'
+      - '*.md'
+
+jobs:
+  build-windows:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run './build.cmd ci'
+        run: ./build.cmd ci
+
+  build-linux:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run './build.cmd ci'
+        run: ./build.sh ci
+
+  publish:
+    runs-on: ubuntu-latest
+    needs: [ build-windows, build-linux ]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Publish
+        run: ./build.sh publish
+        env:
+          NuGetApiKey: ${{ secrets.NUGET_API_KEY }}