Add collector attribute and visibility reporting

[chris-rock]

This audit cookbook PR adds a new method for collecting inspec reports via data_collector(Chef Visibility)

After the code review, these are the remaining tasks

• add unit tests for the classes
• document the new 'collector' attribute
  • breaking change for those using the compliance token path since the 'collector' attribute defaults to 'chef-server'
• need to test the other two collecting methods, chef-server and chef-compliance

This work was done by @alexpop

[alexpop]

Current enriched data added to the report:

          "event_action": "exec",
          "event_type": "inspec",
          "compliance_summary": {
            "total": 11,
            "end_time": "2016-07-22T19:14:08+01:00",
            "node_name": "chef-client.solo",
            "passed": {
              "total": 3
            },
            "failed": {
              "total": 6,
              "minor": 3,
              "major": 2,
              "critical": 1
            },
            "skipped": {
              "total": 2
            },
            "status": "failed",
            "duration": 0.063081,
            "inspec_version": "0.28.0"
          }

When multiple profiles are executed, these only one report that aggregates profile results and summary information.

Hashes like profiles and controls that have user definable keys are also converted into arrays of hashes.

[arlimus]

@alexpop Kudos for this huge change!!

@chris-rock @alexpop just one more thing in this review: could we extract the blob from the actual test:
https://github.com/chef-cookbooks/audit/pull/72/files#diff-9a9a9e0554d7eea4f1d1744ab333cfdeR27
I had a hard time reading the actual test with the huge blob in the middle ;)

In either case, this is 👍 from my side.

[alexpop]

Appreciate the valid feedback Dom, I pushed a new commit.

[chris-rock]

Thanks @alexpop