Fixes container restart crashloop (#57)
Fixes container restart crashloop (#57)

* Adding code in jupyterhub.sh to prevent container to crash loop when restarted.

* Add comment for requiring to remove jupyterhub-proxy.id

* Add file exist check

* Create a function for the code
GoogleCloudDataproc/jupyterhub-dataprocspawner,GoogleCloudDataproc/jupyterhub-dataprocspawner,GoogleCloudDataproc/jupyterhub-dataprocspawner