Bring stage jumpbox config in line with prod

@stvstnfrd This is how I give people access to jump stage; I make sure they're in this file, and I run:
```
ANSIBLE_CONFIG=stage-ansible.cfg ANSIBLE_EC2_INI=stage-ec2.ini ansible-playbook stage-jumpbox.yml -u ubuntu -c ssh -i ./ec2.py -t users
```
Once you've perused, please just go ahead and hit the button. :)