Dependencies to add the local helm chart

[sgibson91]

• name: ingress-nginx / repository: https://kubernetes.github.io/ingress-nginx
• name: cert-manager / repository: https://charts.jetstack.io
• name: prometheus / repository: https://kubernetes-charts.storage.googleapis.com
• name: grafana / repository: https://kubernetes-charts.storage.googleapis.com

[sgibson91]

Configure dashboards https://github.com/jupyterhub/grafana-dashboards