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/8/expected.json

@@ -54,7 +54,8 @@
             "end": {
               "line": 1,
               "column": 9
-            }
+            },
+            "identifierName": "Foo"
           },
           "name": "Foo"
         },
@@ -84,7 +85,8 @@
               "end": {
                 "line": 1,
                 "column": 27
-              }
+              },
+              "identifierName": "Bar"
             },
             "name": "Bar"
           },
@@ -116,7 +118,8 @@
                   "end": {
                     "line": 1,
                     "column": 42
-                  }
+                  },
+                  "identifierName": "Bat"
                 },
                 "name": "Bat"
               },
@@ -157,7 +160,7 @@
           "body": []
         }
       }
-    ]
-  },
-  "comments": []
+    ],
+    "directives": []
+  }
 }