Allow nodeSelector and tolerations to be specified for vault pods

[norwoodj]

At present, the Pod field on the VaultService type offers the ability to specify resource limites/requests for the Vault pods that are deployed. It does not however offer the ability to specify tolerations or a node selector for these pods. We run on Amazon EKS, and would like to run our vault pods on dedicated nodes such that we don't have to assign vault-related IAM permissions to the worker nodes who run our applications. In order to do this, we need the ability to specify these fields.

Add tolerations and nodeSelector fields to the VaultService API object, and use the values of those fields when creating/updating the Vault Deployment object.