gistfile1.txt

I was able to solve this same problem (or an apparently similar one) by patching a crd that turned out to be the cause of the problem.

First I identified the offending crd with the command
$ kubectl get crd
NAME CREATED AT
bgpconfigurations.crd.projectcalico.org 2018-10-24T14:06:47Z
clusterinformations.crd.projectcalico.org 2018-10-24T14:06:47Z
clusters.rook.io 2019-02-05T08:36:08Z
felixconfigurations.crd.projectcalico.org 2018-10-24T14:06:47Z
globalnetworkpolicies.crd.projectcalico.org 2018-10-24T14:06:47Z
globalnetworksets.crd.projectcalico.org 2018-10-24T14:06:47Z
hostendpoints.crd.projectcalico.org 2018-10-24T14:06:47Z
ippools.crd.projectcalico.org 2018-10-24T14:06:47Z
networkpolicies.crd.projectcalico.org 2018-10-24T14:06:47Z

Then I issued the following command:
$ kubectl patch crd clusters.rook.io -p '{"metadata":{"finalizers": []}}' --type=merge

At this point, the crd and the namespace, that I had previously, unsuccessfully, tried to delete, were automatically removed.