Tweak ansible-playbook call to get around Ansible: no hosts matched

[JasPanesar]

Without this change, the tasks in the ansible-playbook would not run.

In trying to get the development environment up and running, executing the existing ansible-playbook command referred to an issue described here: https://stackoverflow.com/questions/38203317/ansible-no-hosts-matched

I am not sure if this is the best, or correct solution, but adding an -i inventory.yml included the already existing inventory file explicitly in the ansible-playbook call and most of the installation seemed to work.