Create superuser at pulsar admin dashboard

create-superuser-for-pulsar-admin-dashboard

1. Follow the [instructions](http://pulsar.apache.org/docs/en/administration-dashboard/) to start the pulsar admin dashboard.
2. Create super user
   1. ssh to the dashboard docker container: `docker exec -it <docker-id> bash`
   2. go to `/pulsar/django` directory in the docker container: `cd /pulsar/django`
   3. run python manage.py to create a superuser: `python manage.py createsuperuser --username admin`
   4. once the superuser is created, you can go to [http://localhost/admin](http://localhost/admin) to login.