TheWeatherCompany/grid-api#1212 Add support for instance-store/ephemeral drives.

PR for TheWeatherCompany/grid-api#1212
actually I didn't change the block of code for checking _IOOptimized_.  the only  this check was added ```va.volumeToCreate.getVolumeProductId() != null && va.volumeToCreate.getVolumeProductId().equalsIgnoreCase(EphemeralVolume.VOLUME_PRODUCT_EPHEMERAL)``` to set correct value. So just to be sure, should I still remove the following block of code? 
 ```if( volType == null ) {
  if( options.getIOOptimized() && va.volumeToCreate.getIops() > 0 ) {
  parameters.put("BlockDeviceMappings.member." + z + ".Ebs.VolumeType", "io1");
  }
 }```