Execute playbook with the incoming clusters data

[arbulu89]

Execute the actual ansible playbook.

For that, the execution inventories are created based on the ExecutionEvent coming from the /api/execute call.

The python callbacks code has not been changed yet. This will come in a subsequent PR. By now, the callbacks just sends the old structure.

This is an example of a request:

{
   execution_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71244",
   clusters: [
      {
         cluster_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71244",
         provider: "azure",
         checks: [
            "156F64",
            "53D035",
            "A1244C"
         ],
         hosts: [
            {
               host_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71241",
               address: "10.162.29.43",
               user: "root"
            },
            {
               host_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71240",
               address: "10.162.30.229",
               user: "root"
            }
         ]
      },
      {
         cluster_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71245",
         provider: "azure",
         checks: [
            "845CC9",
            "24ABCB"
         ],
         hosts: [
            {
               host_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71243",
               address: "10.162.29.43",
               user: "root"
            },
            {
               host_id: "779cdd70-e9e2-58ca-b18a-bf3eb3f71246",
               address: "10.162.30.226",
               user: "root"
            }
         ]
      }
   ]
}

[nelsonkopliku]

LGTM