Description of problem:
cephmetrics-ansible playbook.yml needs package pyYAML to be installed for task 'TASK [ceph-grafana : Push dashboards to Grafana]', however the playbook never checks if it is so and install the package if required.


Version-Release number of selected component (if applicable):
cephmetrics-ansible-1.0-1.el7cp.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Don't install PyYAML on ceph-grafana machine, if it's already installed remove it from the machine
2. Run cepmetrics-ansible playbook playbook.yml
3.

Actual results:
The playbook fails on task 'TASK [ceph-grafana : Push dashboards to Grafana]' with following error:
"ImportError: No module named yaml"


Expected results:
Playbook installs PyYAML on the machine before the task 'TASK [ceph-grafana : Push dashboards to Grafana]' is run.

Additional info: