update documentation

Author: Jan Morawietz

README.md

@@ -36,8 +36,27 @@ if (process.env.NODE_ENV !== 'production') {
 |Key|Description|Default|Required|
 |---|---|---|---|
 |`clearConsoleOnUpdate`|Clears the console each time `vue-axe` runs|`true`|`false`|
+|`customResultHandler`|Handle the results from an `axe.run()`. This may be needed for automated tests.|`undefined`|`false`|
 |`config`|Provide your Axe-core configuration: https://github.com/dequelabs/axe-core/blob/master/doc/API.md#api-name-axeconfigure| |`false`|
 
+#### Custom Result Handler
+
+The `customResultHandler` config property expects a callback like the `axe.run()` callback ([see documentation](https://github.com/dequelabs/axe-core/blob/master/doc/API.md#parameters-axerun)). It will be triggered after each call to `axe.run()`. 
+
+```javascript
+import Vue from 'vue'
+
+if (process.env.NODE_ENV !== 'production') {
+  const VueAxe = require('vue-axe')
+  Vue.use(VueAxe, {
+    customResultHandler: (error, results) => {
+      results.violations.forEach(violation => console.log(violation))
+    }
+    // ...
+  })
+}
+``` 
+
 ## Install in Nuxt.js
 Create plugin file `plugins/axe.js`
 ```javascript

package-lock.json

@@ -59,6 +59,6 @@
     "vue-template-compiler": "^2.6.11"
   },
   "dependencies": {
-    "axe-core": "^3.4.1"
+    "axe-core": "3.5.3"
   }
 }

package.json

@@ -31,7 +31,7 @@ export function checkAndReport (options, node) {
   return deferred.promise
 }
 
-const standardResultHandler = function(error, results) {
+const standardResultHandler = function (errorInfo, results) {
   results.violations = results.violations.filter(result => {
     result.nodes = result.nodes.filter(node => {
       let key = node.target.toString() + result.id