sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install python3.6
sudo apt-get install python3.6-dev

virtualenv --python=`which python3.6` appium_tests
pip install -r .meta/packages

$ npm install -g appium

Place .apk file to app folder: f.e: ./app/Carousell-test-engineering-app.apk
$ py.test -s -v

$ flake8

Assuming that you've installed everything correctly, I mean you have $ANDROID_HOME leading to your android sdk
there is a utils/bootstrap.sh script that downloads sdk and creates a virtual device to run tests.
Because I've faced an issue while doing test task on AVD based on android 7.x:
https://github.com/appium/appium/issues/7588
I've decided to switch to android 6.x and create this sh script to configure environment.
Usage example ./bootstrap.sh to download and create avd or ./bootstrap.sh -run to + run emulator

The demonstration of tests execution you can find in videos folder