Update Dockerfile

Dockerfiles/django/Dockerfile

@@ -1,6 +1,9 @@
 FROM debian:stable-slim
 
-ENV PYTHONUNBUFFERED: 1
+# Prevents Python from writing pyc files to disc (equivalent to python -B option)
+ENV PYTHONDONTWRITEBYTECODE 1
+# Prevents Python from buffering stdout and stderr (equivalent to python -u option)
+ENV PYTHONUNBUFFERED 1
 
 # set work directory
 WORKDIR /usr/src/app