add requirement expression in metadata of task

[Dan33l]

Pull Request (PR) descriptionly

The current task expect Puppet agent installed on the remote.

If it is missing on the remote we get the following error message :

 bolt task run yum action=update --nodes node1 --modulepath ./modules
Started on node1...
Failed on node1:
  The task failed with exit code 126:
  bash: /tmp/594417c7-c1ef-4956-b9ba-b07933580923/init.rb: /opt/puppetlabs/puppet/bin/ruby: bad interpreter: Aucun fichier ou dossier de ce type
 
  {
  }
Failed on 1 node: node1
Ran on 1 node in 0.81 seconds

This PR add the expression of the requirement in bolt. This should permit to get a nicer error message:

bolt task run yum action=update --nodes node1 --modulepath ./modules
Started on node1...
Failed on node1:
  No suitable implementation of yum for node1
Failed on 1 node: node1
Ran on 1 node in 0.15 seconds

[smortex]

This is using 4 spaces for indentation while the rest of the file use 2 space indentation.

Also, with this change, I experience failures on code I am working on:

{
  "kind": "bolt/run-failure",
  "msg": "Plan aborted: run_task 'yum' failed on 2 nodes",
  "details": {
    "action": "run_task",
    "object": "yum",
    "result_set": [
      {
        "node": "aaa",
        "target": "aaa",
        "action": null,
        "object": null,
        "status": "failure",
        "result": {
          "_error": {
            "kind": "bolt/no-implementation",
            "msg": "No suitable implementation of yum for aaa",
            "details": {
            }
          }
        }
      },
      {
        "node": "bbb",
        "target": "bbb",
        "action": null,
        "object": null,
        "status": "failure",
        "result": {
          "_error": {
            "kind": "bolt/no-implementation",
            "msg": "No suitable implementation of yum for bbb",
            "details": {
            }
          }
        }
      }
    ]
  }
}

Reverting this change (or using the latest tagged version of the module, 4.0.0), fixes this issue:

[
  [
    {
      "node": "aaa",
      "target": "aaa",
      "action": "task",
      "object": "yum",
      "status": "success",
      "result": {
        "status": [
          {
            "package": "puppet-agent.x86_64",
            "available_version": "6.6.0-1.el7",
            "repository": "puppet6"
          }
        ]
      }
    },
    {
      "node": "bbb",
      "target": "bbb",
      "action": "task",
      "object": "yum",
      "status": "success",
      "result": {
        "status": [

        ]
      }
    }
  ]
]

[smortex]

(This is CentOS installed with the AIO package, so I guess something is broken)