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 }}

.github/workflows/publish.yml

@@ -0,0 +1,39 @@
+name: Publish
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    env:
+        DOTNET_NOLOGO: true
+        DOTNET_CLI_TELEMETRY_OPTOUT: 1
+
+    steps:
+    - name: Checkout source code
+      uses: actions/checkout@v2
+
+    - name: Setup dotnet 2.1
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 2.1.*
+
+    - name: Setup dotnet 3.1
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.*
+
+    - name: Setup dotnet 5.0
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 5.0.*
+
+    - name: Test
+      run: ./build.cmd ci test pack
+
+    - name: Push with dotnet
+      run: dotnet nuget push artifacts/*.*nupkg --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json