Clarify IAM role and policy
Clarify IAM role and policy

paulbellamy/weave,paulbellamy/weave,paulbellamy/weave,weaveworks/weave,n054/weave,weaveworks/weave,n054/weave,n054/weave,weaveworks/weave,paulbellamy/weave,n054/weave,n054/weave,weaveworks/weave