Added handling for AWS describe-instances not working as expected right away after a successful launch (e.g. InvalidInstanceID.NotFound). Also added checks in _wait_for_full_initialization in case AWS returns a blank status.
Added handling for AWS describe-instances not working as expected right away after a successful launch (e.g. InvalidInstanceID.NotFound). Also added checks in _wait_for_full_initialization in case AWS returns a blank status.

pdanford/launch_ec2_spots