Delete failed helm releases to prevent test case failure (#393)

test/test_utils.sh

@@ -118,6 +118,9 @@ helm_install_fission() {
 
     helm_setup
 
+    echo "Deleting failed releases"
+    helm list --failed -q|xargs -I@ bash -c "helm delete @"
+    
     echo "Installing fission"
     helm install		\
 	 --wait			\
@@ -127,6 +130,8 @@ helm_install_fission() {
 	 --namespace $ns        \
 	 --debug                \
 	 $ROOT/charts/fission-all
+    
+    helm list
 }
 
 wait_for_service() {