CI: add initial configuration for Cirrus

.cirrus.yml

@@ -0,0 +1,40 @@
+container:
+  image: cirrusci/android-sdk:28
+  cpu: 4
+  memory: 8G
+
+task:
+  name: Run tests
+  script: ./gradlew test
+
+task:
+  name: Build release apk
+
+  depends_on:
+    - Run tests
+
+#  environment:
+#    KEYSTORE:
+#    KEYSTORE_PASSWORD:
+
+  build_release_apk_script: |
+    ./gradlew assembleRelease
+
+  build_apksigner_script: |
+    cd ../
+    git clone https://github.com/fornwall/apksigner
+    cd apksigner
+    ./gradlew
+    cp ./build/libs/apksigner-all.jar /tmp/apksigner.jar
+
+  sign_release_apk_script: |
+    echo "$KEYSTORE" | base64 -d > keystore.jks
+    java -jar /tmp/apksigner.jar -p "$KEYSTORE_PASSWORD" keystore.jks \
+      ./app/build/outputs/apk/release/app-release-unsigned.apk \
+      ./termux-release-g${CIRRUS_CHANGE_IN_REPO:0:8}.apk
+
+  release_artifacts:
+    path: "./*.apk"
+
+  unsigned_artifacts:
+    path: "./app/build/outputs/apk/release/*.apk"