- React to all verbs, not just "create"

- When a namesapce is deleted, delete all contained resources

- Update unit tests

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

If a namespace is deleted and the namespace was previously seen,
ie there was at least one resource previously synced in that namespace,
then retrieve all the cached resource keys in the namespace and add them
to the missingNamespaces set. If the namespace is later recreated,
then those resources will be re-queued and re-synced.

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>