Start a session to an EC2 instance
thief ec2 session [flags]
-h, --help help for session
-i, --instance-id string Instance ID
--no-header Hide the header in output
-o, --output string Output format (tab/csv) (default "tab")
-p, --profile string AWS profile (default $AWS_PROFILE)
-r, --region string AWS region (default "ap-northeast-1")