Migrate Windows 2016 env to GitHub Actions from AzurePipelines

.github/workflows/windows-2016.yml

@@ -0,0 +1,29 @@
+name: windows-2016
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  latest:
+    runs-on: windows-2016
+    steps:
+      - name: Install libraries with vcpkg
+        run: |
+          vcpkg --triplet x64-windows install %dependencies% || (
+            sleep 4 && vcpkg --triplet x64-windows install %dependencies%
+          ) || (
+            sleep 25 && vcpkg --triplet x64-windows install %dependencies%
+          )
+        env:
+          dependencies: openssl readline zlib
+      - name: Install libraries with chocolatey
+        run: choco install winflexbison3
+      - name: Checkout # not using actions/checkout because it's unstable.
+        run: git clone --depth=50 https://github.com/ruby/ruby .
+      - name: configure
+        run: |
+          call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          win32/configure.bat --without-ext=+,dbm,gdbm --enable-bundled-libffi --with-opt-dir=C:/vcpkg/installed/x64-windows