Merge pull request #138 from hanabi1224/cirrus_ci

.ci/Dockerfile

+FROM cirrusci/flutter:stable
+
+RUN sudo apt-get update -y
+
+RUN sudo apt-get install -y --no-install-recommends gnupg
+
+# Add repo for gcloud sdk and install it
+RUN echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] https://packages.cloud.google.com/apt cloud-sdk main" | \
+    sudo tee -a /etc/apt/sources.list.d/google-cloud-sdk.list 
+
+RUN curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | \
+    sudo apt-key --keyring /usr/share/keyrings/cloud.google.gpg add -
+
+RUN sudo apt-get update && sudo apt-get install -y google-cloud-sdk && \
+    gcloud config set core/disable_usage_reporting true && \
+    gcloud config set component_manager/disable_update_check true
+
+RUN yes | sdkmanager \
+    "platforms;android-29" \
+    "build-tools;29.0.2" \
+    "extras;google;m2repository" \
+    "extras;android;m2repository"
+
+RUN yes | sdkmanager \
+    "platforms;android-28" \
+    "build-tools;28.0.3" \
+    "extras;google;m2repository" \
+    "extras;android;m2repository"
+
+RUN yes | sdkmanager --licenses

.cirrus.yml

+task:
+  container:
+    dockerfile: .ci/Dockerfile
+    cpu: 8
+    memory: 16G
+  pub_cache:
+    folder: ~/.pub-cache
+  setup_script:
+    - flutter channel stable
+    - flutter upgrade
+  build_script: 
+    - cd example
+    - flutter build apk
+  #test_script: flutter test
+
+task:
+  osx_instance:
+    image: mojave-flutter
+  pub_cache:
+    folder: ~/.pub-cache
+  setup_script:
+    - pod repo update
+    - flutter channel stable
+    - flutter upgrade
+  create_simulator_script:
+    - xcrun simctl list
+    - xcrun simctl create Flutter-iPhone com.apple.CoreSimulator.SimDeviceType.iPhone-X com.apple.CoreSimulator.SimRuntime.iOS-12-2 | xargs xcrun simctl boot
+  build_script: 
+    - cd example
+    - flutter build ios --no-codesign
+  #test_script: flutter test