Created dockerfile and docker-compose manifest

[aartek]

Hi, I wanted to sync Strava with Endomondo locally due to reached API calls limit, so I've prepared a docker-compose configuration to let it easily start locally. However I've end up with a surprise that there is no possibility to create the endomondo credentials, so finally I didn't sync anything. But here's a PR with my work. Maybe someone will find it useful.

Prerequisites:

• Docker
• Docker Compose (https://docs.docker.com/compose/install/)

How to:

• run docker-compose up -d
• stop docker-compose down
• rebuild in case of any changes (i.e. in local_settings.py.example) docker-compose build

[dsb3]

At first glance this looks good.

Switching from ubuntu: latest to python:3-alpine (and apt-get to apk) is likely to drop container images size by 90%