exact-match target rules can be missed in mahi.authorize()

[arekinath]

Aperture can sometimes return a lookup-object format for exact match rules with targets:

{
        "effect": true,
        "actions": {
          "exact": {
            "getdirectory": true
          },
          "regex": []
        },
        "resources": {
          "exact": {
            "/elipse/stor/builds": true
          },
          "regex": []
        },
        "conditions": []
      }

Currently in mahi.authorize() we're only looking for the array-style exact match, which means we miss this and don't process it as a targetted rule.