Add missing parameter in dockerfile

Dockerfile

@@ -9,6 +9,6 @@ WORKDIR ${APP_HOME}
 #  libpq-dev \
 #  && apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false \
 #  && rm -rf /var/lib/apt/lists/*
-RUN pip install requirements.txt
+RUN pip install -r requirements.txt
 ENTRYPOINT ["python3 -m ontopoint"]
 #CMD ["/start.sh"]