Add GitHub action and remove Travis config

.github/workflows/build-app-workflow.yaml

@@ -0,0 +1,10 @@
+name: Build
+on: [pull_request, push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the code
+        uses: actions/checkout@v2
+      - name: Build the app
+        run: ./gradlew build

.travis.yml

@@ -1,24 +0,0 @@
-language: shell
-os: linux
-dist: bionic
-env:
-  global:
-    - ANDROID_HOME=${HOME}/android
-    - ANDROID_SDK_ROOT=${ANDROID_HOME}
-    - TOOLS=${ANDROID_HOME}/cmdline-tools
-    - PATH=${ANDROID_HOME}/emulator:${TOOLS}/tools/bin:${ANDROID_HOME}/platform-tools:${PATH}
-before_install:
-  - mkdir -p ${ANDROID_HOME}/licenses
-  - echo "8933bad161af4178b1185d1a37fbf41ea5269c55" > ${ANDROID_HOME}/licenses/android-sdk-license
-  - echo "d56f5187479451eabf01fb78af6dfcb131a6481e" >> ${ANDROID_HOME}/licenses/android-sdk-license
-  - echo "24333f8a63b6825ea9c5514f83c2829b004d1fee" >> ${ANDROID_HOME}/licenses/android-sdk-license
-install:
-  - mkdir -p ${TOOLS}
-  - travis_retry wget https://dl.google.com/android/repository/commandlinetools-linux-6514223_latest.zip -O ${TOOLS}/tools.zip
-  - unzip ${TOOLS}/tools.zip -d ${TOOLS}
-  - yes | travis_retry sdkmanager "platform-tools" > /dev/null
-  - yes | travis_retry sdkmanager "tools" > /dev/null
-  - yes | travis_retry sdkmanager "build-tools;30.0.1" > /dev/null
-  - yes | travis_retry sdkmanager "platforms;android-30" > /dev/null
-script:
-  - ./gradlew assemble check