tester in docker works

Dockerfile

@@ -1,13 +1,18 @@
-FROM python:3.7
+FROM docker:dind
+
+RUN apk add --update --no-cache python3 && ln -sf python3 /usr/bin/python
+RUN python3 -m ensurepip
+RUN apk update && apk add postgresql-dev gcc python3-dev musl-dev jpeg-dev zlib-dev libjpeg
+RUN pip3 install --no-cache --upgrade pip setuptools
+RUN addgroup -S docker
 
 ENV PYTHONUNBUFFERED 1
 ENV DJANGO_SETTINGS_MODULE Sprint.settings
 RUN mkdir -p /usr/src/app/
 WORKDIR /usr/src/app/
 
-COPY . /usr/src/app/
+COPY ../.. /usr/src/app/
 
-RUN pip install --upgrade pip wheel setuptools
-RUN pip install -r requirements.txt
+RUN pip3 install -r requirements.txt
 
 EXPOSE 8000