Waldo integration with Travis CI requires you only to add a few steps to your .travis.yml:

env:
  global:
    - WALDO_CLI_BIN=/usr/local/bin
    - WALDO_UPLOAD_TOKEN=<<waldoUploadToken>>
install:
  - bash -c "$(curl -fLs https://github.com/waldoapp/waldo-go-cli/raw/master/install-waldo.sh)"
script:
  #...
  #... Build your APK
  #...
  - ${WALDO_CLI_BIN}/waldo upload "/path/to/YourApp.apk"

Make sure you use your "CI Token" (you can find it in: Sidebar > Configuration > General. We make sure tokens used in CI are only scoped to a specific app, as a result CI uploads won't work with your User token (that you can find in user menu > Account settings > Profile).