Allow es6 in mocha tests lint check (#4062)

* Allow es6 in mocha tests.

tests/mocha/.eslintrc.json

@@ -1,4 +1,5 @@
 {
+    "parser": "babel-eslint",
     "env": {
         "browser": true,
         "mocha": true
@@ -20,5 +21,28 @@
         "getXmlArray": true,
         "getCategoryJSON": true
     },
+    "rules": {
+        "no-unused-vars": ["off"],
+        "es5/no-arrow-functions": ["off"],
+        "es5/no-binary-and-octal-literals": ["off"],
+        "es5/no-block-scoping": ["off"],
+        "es5/no-classes": ["off"],
+        "es5/no-computed-properties": ["off"],
+        "es5/no-default-parameters": ["off"],
+        "es5/no-destructuring": ["off"],
+        "es5/no-es6-methods": ["off"],
+        "es5/no-es6-static-methods": ["off"],
+        "es5/no-for-of": ["off"],
+        "es5/no-generators": ["off"],
+        "es5/no-modules": ["off"],
+        "es5/no-object-super": ["off"],
+        "es5/no-rest-parameters": ["off"],
+        "es5/no-shorthand-properties": ["off"],
+        "es5/no-spread": ["off"],
+        "es5/no-template-literals": ["off"],
+        "es5/no-typeof-symbol": ["off"],
+        "es5/no-unicode-code-point-escape": ["off"],
+        "es5/no-unicode-regex": ["off"]
+    },
     "extends": "../../.eslintrc.json"
 }

tests/mocha/test_helpers.js

@@ -4,9 +4,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-/* exported assertVariableValues, captureWarnings, defineRowBlock,
-   defineStackBlock, defineStatementBlock, createTestBlock, createEventsFireStub */
-
 /**
  * Check if a variable with the given values exists.
  * @param {Blockly.Workspace|Blockly.VariableMap} container The workspace  or

tests/mocha/toolbox_helper.js

@@ -4,9 +4,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-
-/* exported getCategoryJSON, getSimpleJSON, getXmlArray */
-
 /**
  * Get JSON for a toolbox that contains categories.
  * @return {Array.<Blockly.utils.toolbox.Toolbox>} The array holding information