[ansible] `become` privilege escalation issues

[arm4b]

Running Ansible via StackStorm pack with privilege escalation options like become doesn't work (?).

When running Ansible pack with command equivalent:

Executed command "/opt/stackstorm/virtualenvs/ansible/bin/ansible-playbook --become-user=ubuntu --inventory-file=/home/ubuntu/configurations/ansible/hosts --become --become-method=su /home/ubuntu/configurations/ansible/staging.yml"

Ansible can't read ~/.ssh/config of ubuntu user.

Reported by @vikrantpogula:

Ansible playbook is not able to resolve the hostnames because my playbook uses hostnames from the ~/.ssh/config
Basically instead of saying <IP_ADDRESS> in my playbook i just use a Hostname which is then pointed to the actual servers ip address (using the config file)

[vikrantpogula]

Link for knowing about ForwardAgent. https://developer.github.com/guides/using-ssh-agent-forwarding/

This lets the ssh keys (like github) in the Host system's ssh-agent to be forwarded to the ssh-ed system. This eliminates adding ssh access keys to each target node

[LindsayHill]

Track here: StackStorm-Exchange/stackstorm-ansible#16