Use up to date poetry installation command

Dockerfile

@@ -12,7 +12,7 @@ COPY poetry.lock pyproject.toml /app/
 WORKDIR /app/
 
 RUN pip install -U poetry && \
-    poetry install --no-dev
+    poetry install --only main
 
 COPY fabcal /app/fabcal/
 COPY static/ /app/static/