Test runner: Detect extra property in 'actual' but not in 'expected'. (#407)

* Test runner: Detect extra property in 'actual' but not in 'expected'.

Also update all expected.json where this would result in errors.

* Include rmExpected.js script in case it is needed again

test/fixtures/flow/interfaces-module-and-script/1/expected.json

@@ -54,12 +54,14 @@
             "end": {
               "line": 1,
               "column": 11
-            }
+            },
+            "identifierName": "A"
           },
           "name": "A"
         },
         "typeParameters": null,
         "extends": [],
+        "mixins": [],
         "body": {
           "type": "ObjectTypeAnnotation",
           "start": 12,
@@ -76,10 +78,11 @@
           },
           "callProperties": [],
           "properties": [],
-          "indexers": []
+          "indexers": [],
+          "exact": false
         }
       }
-    ]
-  },
-  "comments": []
+    ],
+    "directives": []
+  }
 }