Refactor much needed docker setup

- Build static files inside seperate container
- Remove unnecessary env variables

docker/django

@@ -0,0 +1,10 @@
+FROM python:3.7-buster
+
+RUN pip install poetry
+
+WORKDIR /app
+COPY poetry.lock pyproject.toml /app/
+
+RUN poetry config virtualenvs.create false && poetry install --no-interaction
+
+COPY . /app/