GitHub action to build RR on windows

.github/workflows/build.yaml

@@ -0,0 +1,31 @@
+name: RomRaider build
+
+on: [push,pull_request]
+
+jobs:
+  build:
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - name: Setup Java 8
+        uses: actions/setup-java@v1.4.3
+        with:
+          java-version: '8'
+          java-package: jdk
+          architecture: x64
+      - name: set JRE_DIR environment variable
+        shell: bash
+        env:
+          ACTIONS_ALLOW_UNSECURE_COMMANDS: true
+        run: echo ::set-env name=JRE_DIR::$(echo $JAVA_HOME)/jre
+
+      - name: Test Compiler
+        run: javac -version
+
+      - name: All
+        run: |
+          echo JRE_DIR=$JRE_DIR
+          ant all