title: Not able to assign elastic ip using knife
body: <p>I want to create a EC2 instance using knife with an elastic IP assigned to it. Knife has the option <code>--associate-eip</code> but when I use this option it fails with error </p>
  
  <blockquote>
    <p>ERROR: Elastic IP requested is not available. </p>
  </blockquote>
  
  <p>even though the EIP in AWS console shows the IP is available.</p>
  
  <p>The command I executed</p>
  
  <blockquote>
    <p>knife ec2 server create -S testKey -I ami-e7b8c0d7 --security-group-id test_sg -N test-eip -f m3.medium --region us-west-2 -i testKey.pem --associate-eip 6.6.6.6</p>
  </blockquote>
  
  <p>Did I miss any obvious steps? Where does knife look for the elastic ip list? Is there a place to inform about the elastic IP list to knife?</p>