Update Dockerfile

Dockerfile

@@ -44,7 +44,7 @@ COPY ./ .
 # Create PostgreSQL users and databases in the background
 #RUN service redis-server start \
 #    && service postgresql start 
-RUN apt-get update && apt-get install -y supervisor redis-server postgresql-12
+RUN apt-get update && apt-get install -y supervisor redis-server postgresql
 
 # Copying supervisor configuration file to container
 ADD supervisor.conf /etc/supervisor.conf