Update Dockerfile

Author: And[re]y Bar[a]nov

Dockerfile

@@ -2,3 +2,5 @@ FROM python:3.8.6-slim-buster
 RUN apt-get update && apt-get install -y --no-install-recommends make
 COPY requirements.txt /requirements.txt
 RUN pip install -r /requirements.txt
+
+WORKDIR /data-challenges