Adds GitHub Action workflow which duplicates AppVeyor job.

Author: sipsorcery

.github/workflows/ci.yml

@@ -0,0 +1,76 @@
+name: bitcoin-core-ci
+
+on:
+  push:
+jobs:
+  build:
+    runs-on: windows-latest
+    env:
+        PYTHONUTF8: 1
+        QT_DOWNLOAD_URL: 'https://github.com/sipsorcery/qt_win_binary/releases/download/v1.4/Qt5.9.8_x64_static_vs2019.zip'
+        QT_DOWNLOAD_HASH: 'f285cbb02bec3b3f3cc2621e3fa7d5edf0d6a66fa30c57859e583acda954ea80'
+        QT_LOCAL_PATH: 'C:\Qt5.9.8_x64_static_vs2019'
+        VCPKG_INSTALL_PATH: "$env:VCPKG_INSTALLATION_ROOT/installed"
+        PLATFORM: x64
+    steps:
+    - uses: actions/checkout@v1
+
+    - uses: actions/cache@v1
+      id: vcpkgcache
+      with:
+       path: C:/vcpkg/installed
+       key: ${{ runner.os }}-vcpkg
+
+    - name: Update vcpkg and install packages
+      if: steps.vcpkgcache.outputs.cache-hit != 'true'
+      run: |
+        $env:PACKAGES = Get-Content -Path "$env:GITHUB_WORKSPACE/build_msvc/vcpkg-packages.txt"
+        Write-Host "vcpkg list: $env:PACKAGES"
+        cd $env:VCPKG_INSTALLATION_ROOT
+        git pull origin master
+        .\bootstrap-vcpkg.bat
+        .\vcpkg install --triplet $env:PLATFORM-windows-static $env:PACKAGES.split() > $null
+    - name: Install prebuilt Qt libraries
+      run: |
+       if(!(Test-Path -Path ($env:QT_LOCAL_PATH))) {
+          Write-Host "Downloading Qt binaries.";
+          Invoke-WebRequest -Uri $env:QT_DOWNLOAD_URL -Out qtdownload.zip;
+          Write-Host "Qt binaries successfully downloaded, checking hash against $env:QT_DOWNLOAD_HASH...";
+          if((Get-FileHash qtdownload.zip).Hash -eq $env:QT_DOWNLOAD_HASH) {
+            Expand-Archive qtdownload.zip -DestinationPath $env:QT_LOCAL_PATH;
+            Write-Host "Qt binary download matched the expected hash.";
+          }
+          else {
+            Write-Host "ERROR: Qt binary download did not match the expected hash.";
+            exit 1
+          }
+        }
+        else {
+           Write-Host "Qt binaries already present.";
+        }
+    - name: Generate project files
+      run: python build_msvc\msvc-autogen.py
+    - name: Setup MSBuild.exe
+      uses: warrenbuckley/Setup-MSBuild@v1
+    - name: vcpkg integration
+      run: C:/vcpkg/vcpkg.exe integrate install
+    - name: Build
+      run: msbuild build_msvc\bitcoin.sln /m /v:n /p:Configuration=Release
+    - name: Run test_bticoin
+      shell: cmd
+      run: src\test_bitcoin.exe -k stdout -e stdout 2> NUL
+    - name: Run bench_bitcoin
+      shell: cmd
+      run: src\bench_bitcoin.exe -evals=1 -scaling=0 > NUL
+    - name: bitcoin-util-test
+      run: python test\util\bitcoin-util-test.py
+    - name: rpcauth-test
+      shell: cmd
+      run: python test\util\rpcauth-test.py
+# This step fails due to character UTF encoding error. If anyone knows how Python deals with Unicode they might be
+# able to decipher the error message.
+#    - name: test_runner
+#      shell: cmd
+#      run: |
+#       python test\functional\test_runner.py --ansi --ci --quiet --combinedlogslen=4000 --failfast --exclude feature_fee_estimation
+