ST-1269: Setting up policies for BinderHub

Set up policies for:

• Pod timeout: jupyterhub.cull.timeout = 7200
• Storage retention: once a PVC is created for a user it only gets deleted if a JupyterHub Admin does it manually, otherwise even if the pods get deleted when the server is shutdown the PVC will be kept. If the server gets deleted, instead of shutdown, the pvc is also deleted.
• User Management
  • Notebooks limit: jupyterhub.hub.namedServerLimitPerUser = 5
  • Storage limit: jupyterhub.singleuser.storage.capacity = 2Gi
• Resource usage(set per user too)
  • CPU: jupyterhub.singleuser.cpu.limit = 1 and jupyterhub.singleuser.cpu.guarantee = 1
  • RAM: jupyterhub.singleuser.memory.limit = 2 and jupyterhub.singleuser.memory.guarantee = 2