Fix namespace used in speciallized pod cleanup (#2415)

In pool pod controller we were using pool namespace
rather than pod namespace in cleanup which was causing
issue in few scenarios. Using pod namespace now instead.
Also add unit test for scenario which was failing.
Using kubernetes client interface now across instead of
kubernetes ClientSet for testing.

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/fetcher/config/config.go

@@ -93,7 +93,7 @@ func MakeFetcherConfig(sharedMountPath string) (*Config, error) {
 	}, nil
 }
 
-func (cfg *Config) SetupServiceAccount(kubernetesClient *kubernetes.Clientset, namespace string, context interface{}) error {
+func (cfg *Config) SetupServiceAccount(kubernetesClient kubernetes.Interface, namespace string, context interface{}) error {
 	_, err := utils.SetupSA(kubernetesClient, fv1.FissionFetcherSA, namespace)
 	if err != nil {
 		log.Printf("Error : %v creating %s in ns : %s for: %#v", err, fv1.FissionFetcherSA, namespace, context)