Slim repo and replace MariaDB with PostgreSQL. #4

Dockerfile

-FROM python:3.8-buster
+FROM python:3.8-slim
+
+LABEL maintainer="David Trattnig <david.trattnig@subsquare.at>"
 
 # Initialize the project structure
 
@@ -9,8 +11,9 @@ RUN mkdir -p /var/log/aura
 
 COPY . /srv
 WORKDIR /srv
+RUN /usr/local/bin/python -m pip install --upgrade pip
 RUN pip3 install --no-cache-dir -r requirements.txt
-RUN pip3 install --no-cache-dir -r contrib/mariadb-requirements.txt
+RUN pip3 install --no-cache-dir -r contrib/postgresql-requirements.txt
 ENV PYTHONPATH "${PYTHONPATH}:/srv/src"
 
 # Create default config