Cleanup the whole config-parser class

src/fixtures/expected/nuxt.config.missing.js

@@ -1,9 +1,7 @@
 import {resolve} from 'path'
 
 export default {
-  router: {
-    base: '/amazing-new-repo/'
-  },
+  router: {base: '/amazing-new-repo/'},
   alias: {
     style: resolve(__dirname, './assets/style')
   },

src/fixtures/x.js

@@ -0,0 +1,3 @@
+module.exports = {
+  pathPrefix: "hello",
+};