Check deeper directories for .git when selecting a SCM profiler

Makes the SCM profiling useful when used with a monolithic repo or when using the "app" layout. I tested it with my "policyfile_demo" repo, and ChefDK now collects this git info (where it didn't detect the git repo previously):

```json
    "policyfile_demo": {
      "version": "0.1.0",
      "identifier": "f04cc40faf628253fe7d9566d66a1733fb1afbe9",
      "dotted_decimal_identifier": "67638399371010690.23642238397896298.25512023620585",
      "source": "cookbooks/policyfile_demo",
      "cache_key": null,
      "scm_info": {
        "scm": "git",
        "remote": "git@github.com:danielsdeleo/policyfile-jenkins-demo.git",
        "revision": "89f497d1f008fd8c0fe0c3dc7ef37de9a09c181d",
        "working_tree_clean": false,
        "published": true,
        "synchronized_remote_branches": [
          "mine/master"
        ]
      },
      "source_options": {
        "path": "cookbooks/policyfile_demo"
      }
    },
```

@opscode/client-engineers