PolicyDocument.Statement[].Resource not allowing single element

[mnkg561]

Is this a BUG REPORT or FEATURE REQUEST?:
BUG REPORT

What happened:
AWS IAM Policy has a field Resource which can be single element or multiple elements(or array). iam-manager can unmarshal only if it is an array as Resource defined it as an array in the element.

What you expected to happen:
iam-manager must accept single element for Resource field along with array in the yaml file.

How to reproduce it (as minimally and precisely as possible):
create a role with Resource field having single element and you should see following error

mtvl15367e28a:playerdb nmogulla$ k apply -f /Users/nmogulla/Desktop/Eclipse_Workspace/GoProjects2/src/github.com/keikoproj/iam-manager/config/samples/iammanager_v1alpha1_iamrole.yaml
Error from server (InternalError): error when creating "/Users/nmogulla/Desktop/Eclipse_Workspace/GoProjects2/src/github.com/keikoproj/iam-manager/config/samples/iammanager_v1alpha1_iamrole.yaml": Internal error occurred: admission webhook "miamrole.kb.io" denied the request: v1alpha1.Iamrole.Spec: v1alpha1.IamroleSpec.PolicyDocument: v1alpha1.PolicyDocument.Statement: []v1alpha1.Statement: v1alpha1.Statement.Resource: []string: decode slice: expect [ or n, but found ", error found in #10 byte of ...|esource":"*"},{"Acti|..., bigger context ...|":["sts:AssumeRole"],"Effect":"Allow","Resource":"*"},{"Action":["ec2:Describe*"],"Effect":"Allow","|...
mtvl15367e28a:playerdb nmogulla$ 

Anything else we need to know?:

Environment:

• iam-manager version
• Kubernetes version :

$ kubectl version -o yaml

Other debugging information (if applicable):

- controller logs:

$ kubectl logs