check_rancher2

This release enhances the plugin to check for workloads in a specific namespace. This is necessary when there are multiple workloads with the same name around (for example "nginx") but deployed across multiple namespaces.

This also fixes the pod check which already was prepared to check for pods in namespaces (according to documentation) but was missing to read the namespace given with -n namespace.

This release adds a new parameter "-i" to manually set a list of status(es) to ignore. Currently this only affects checks on nodes (using -t node).

With this change, certain status(es) can be ignored, for example when a node is in cordoned or drained status.

Handles 403 error from API and solves #15