I have a question on AWS cost for metaflow. I set up AWS batch with CloudFormation. I assume that we won't have any EC2 running after batch jobs finish, but I see I have a currently running EC2 of type c4.2xlarge. What's more, when I terminate this EC2 instance it automatically starts another instance of the same type. My question: does metaflow service itself requires an EC2 instance, outside of the batch jobs? Also, what is a normal monthly AWS cost for the situation where you don't run any batch jobs at all? (I am ML hobbyist and I am using Metaflow for my personal project, and I am worried that AWS cost gets out of control. It seems like I already have 80+ dollars on my AWS bill from the past 7 days since I set up CloudFormation, even though I didn't use Batch that much)