title: Error creating IAM Role - Value of property PolicyDocument must be an object
body: <p>I am creating an IAM role in order to send logs from a stack to kinesis stream in another stack.
  When I add permission policy, it fails with the error :</p>
  <blockquote>
  <p>&quot;Value of property PolicyDocument must be an object&quot;.</p>
  </blockquote>
  <p>This is my cloudformation.template.yml :</p>
  <pre><code>  KinesisRole:
      Type: AWS::IAM::Role
      Properties:
        RoleName: {'Fn::Sub': 'Kinesis-Role-${AWS::Region}'}
        AssumeRolePolicyDocument:
          Statement:
          - Effect: Allow
            Principal:
              Service: [logs.amazonaws.com]
            Action: ['sts:AssumeRole']
        Policies:
        - PolicyName: KinesisPolicy
          PolicyDocument:
          - Version: '2017-10-17'
            Statement:
            - Action: ['kinesis:PutRecord']
              Effect: Allow
              Resource: '*'
  </code></pre>