Replace travis with github actions build (#6238)

.github/workflows/build.yml

@@ -0,0 +1,69 @@
+name: Java CI with Gradle
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  macos:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+      - name: Natives cache
+        uses: actions/cache@v2
+        with:
+          path: ~/.ccache
+          key: ${{ runner.os }}-ccache-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-ccache
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+
+      - name: Setup ccache
+        run: |
+          brew install ccache
+          echo "/usr/local/opt/ccache/libexec" >> $GITHUB_PATH
+      - name: Build macOS natives
+        run: ant -f build-mac-ios.xml
+
+  linux:
+    runs-on: ubuntu-latest
+    env:
+      ORG_GRADLE_PROJECT_GITHUB_USERNAME: ""
+      ORG_GRADLE_PROJECT_GITHUB_API_TOKEN: ""
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+      - name: Gradle cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+            ~/.android/build-cache
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+
+      - name: Setup Android build environment
+        uses: android-actions/setup-android@v2
+      - name: Fetch natives
+        run: ./gradlew fetchNatives
+      - name: Build whole project with gradle
+        run: ./gradlew build
+      - name: Upload all output libs
+        uses: actions/upload-artifact@v2.1.4
+        with:
+          name: output-libs
+          path: '**/build/libs/'