More work to integrate skimage with rebaseline tools.

tools/tests/skimage/input/bad-images/incorrect-results.json

 {
    "actual-results" : {
       "failed" : null,
       "failure-ignored" : null,
       "no-comparison" : null,
       "succeeded" : null
    },
    "expected-results" : {
-      "invalid.png" : {
+      "invalid.png_None.png" : {
          "allowed-digests" : [
             [ "bitmap-64bitMD5", 8011846386646810712 ]
          ],
          "ignore-failure" : false
       }
    }
 }