add docker-entrypoint script used in Dockerfile

docker-entrypoint.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+echo "Flush the manage.py command if any"
+
+while ! python manage.py flush --no-input 2>&1; do
+  echo "Flushing django manage command"
+  sleep 3
+done
+
+echo "Migrate the database at startup of project"
+
+while ! python manage.py migrate 2>&1; do
+  echo "Migration is in progress status"
+  sleep 3
+done
+
+echo "Django docker is fully configured successfully."
+
+exec "$@"