jaeger-operator: Settings `WATCH_NAMESPACE` to multiple namespaces does not work

When setting the WATCH_NAMESPACE flag to a comma-separated list as described in the docs, the list actually gets interpreted as one single namespace.

For example setting this:

WATCH_NAMESPACE=namespace1,namespace2

will result in this error:

E0525 08:26:15.626046       1 reflector.go:123] pkg/mod/k8s.io/client-go@v0.0.0-20191016111102-bec269661e48/tools/cache/reflector.go:96: Failed to list *v1.Deployment: deployments.apps is forbidden: User "system:serviceaccount:jaeger-operator:jaeger-operator" cannot list resource "deployments" in API group "apps" in the namespace "namespace1,namespace2"

This is probably due to a bug in the OperatorSDK (https://github.com/operator-framework/operator-sdk/pull/2522) that got fixed with Version 0.16.0

However, if I interpret it correctly (I am not a Go-Pro, pun intended), this repository still uses version 0.15.1.

Would be great if either the version could be increased or the docs could be updated. I can’t do the former (again: not a go-pro 😉 ) but if you say an upgrade of the operator will not be doable, I’ll happily create a PR in the documentation-repository to fix the latter.