Implement leader election and scale JH to 3 pods based on the outcome of https://issues.redhat.com/browse/RHODS-766.

PR  

https://github.com/opendatahub-io/odh-manifests/pull/460

Testing

To test this deployment, follow these steps:

1. On your OC cluster, install the ODH Operator
2. Run a new instance, replacing with the following repository the KfDef file:

```

• name: manifests
  uri: 'https://github.com/lucferbux/odh-manifests/tarball/feature/leader-election'
  ```
  3. Change the `quay.io/odh-jupyterhub/jupyterhub-img:v0.3.0` image to `quay.io/lferrnan/jupyterhub-img:v0.1.7`

For further info you can check this [test log](https://docs.google.com/document/d/1mpDir4GjhSrs3awMOsNKmD3tAME2uks9mW0Gh1q4CKc/edit?usp=sharing)