Replace Travis-CI with GitHub actions (qzind#856)

.github/workflows/build.yaml

@@ -0,0 +1,55 @@
+name: Build QZ Tray
+
+on: [push]
+
+jobs:
+  ubuntu:
+    runs-on: [ubuntu-latest]
+    strategy:
+      matrix:
+        java: [11, 16]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v2
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: 'temurin'
+      - run: sudo apt-get install nsis makeself
+      - run: ant makeself
+      - run: sudo out/qz-tray-*.run
+      - run: /opt/qz-tray/qz-tray --version
+      - run: ant nsis
+
+  macos:
+    runs-on: [macos-latest]
+    strategy:
+      matrix:
+        java: [11, 16]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v2
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: 'temurin'
+      - run: brew install nsis makeself
+      - run: ant pkgbuild
+      - run: sudo installer -pkg out/qz-tray-*.pkg -target /
+      - run: "'/Applications/QZ Tray.app/Contents/MacOS/QZ Tray' --version"
+      - run: ant makeself
+      - run: ant nsis
+
+  windows:
+    runs-on: [windows-latest]
+    strategy:
+      matrix:
+        java: [11, 16]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v2
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: 'temurin'
+      - run: choco install nsis
+      - run: ant nsis
+      - run: Start-Process -Wait ./out/qz-tray-*.exe -ArgumentList "/S"
+      - run: "&'C:/Program Files/QZ Tray/qz-tray.exe' --wait --version|Out-Null"