merge master into dev (#219)

Author: pi0

docs/helpers.md

@@ -17,7 +17,7 @@ Example: (`plugins/axios.js`)
 ```js
 export default function ({ $axios, redirect }) {
   $axios.onError(error => {
-    if(error.code === 500) {
+    if(error.response.status === 500) {
       redirect('/sorry')
     }
   })

docs/options.md

@@ -18,6 +18,8 @@ Base URL which is used and prepended to make requests in server side.
 
 Environment variable `API_URL` can be used to **override** `baseURL`.
 
+**Note:** `baseURL` and `proxy` doesn't work together, you need to use `prefix` instead.
+
 ### `browserBaseURL`
 
 * Default: `baseURL` (or `prefix` when `options.proxy` is enabled)