add CircleCI config file

.circleci/config.yml

@@ -0,0 +1,30 @@
+version: 2
+jobs:
+  build:
+    working_directory: ~/code
+    docker:
+      - image: circleci/android:api-28
+    environment:
+      JVM_OPTS: -Xmx3200m
+    steps:
+      - checkout
+      - restore_cache:
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+      - run:
+          name: Download Dependencies
+          command: echo y | android update sdk --no-ui --all --filter tools,platform-tools,build-tools-28.0.3,android-28,extra-android-m2repository
+      - save_cache:
+          paths:
+            - ~/.gradle
+          key: jars-{{ checksum "build.gradle" }}-{{ checksum  "app/build.gradle" }}
+      - store_artifacts:
+          path: app/build/reports
+          destination: reports
+      - store_test_results:
+          path: app/build/test-results
+      - run:
+          name: Run Build
+          command: ./gradlew build connectedCheck --stacktrace
+      - store_artifacts:
+          path: app/build/outputs/apk/debug/
+          destination: artifact-file