Don't panic when provisioning teams if there is no parent resource defined (#25)

* Don't panic when provisioning teams if there is no parent resource defined

* Use helpers to make sure the resource exists

* Use helpers to make sure the parent resource exists as well

Author: jirwin

pkg/connector/team.go

@@ -266,6 +266,10 @@ func (o *teamResourceType) Grant(ctx context.Context, principal *v2.Resource, en
 		return nil, err
 	}
 
+	if entitlement.GetResource().GetParentResourceId() == nil {
+		return nil, fmt.Errorf("github-connectorv2: parent resource is required to grant team membership")
+	}
+
 	orgId, err := strconv.ParseInt(entitlement.Resource.ParentResourceId.Resource, 10, 64)
 	if err != nil {
 		return nil, err
@@ -311,6 +315,10 @@ func (o *teamResourceType) Revoke(ctx context.Context, grant *v2.Grant) (annotat
 		return nil, err
 	}
 
+	if entitlement.GetResource().GetParentResourceId() == nil {
+		return nil, fmt.Errorf("github-connectorv2: parent resource is required to revoke team membership")
+	}
+
 	orgId, err := strconv.ParseInt(entitlement.Resource.ParentResourceId.Resource, 10, 64)
 	if err != nil {
 		return nil, err