Fixed failing unit test because of leaking state

front/tests/unit/specs/store/instance.spec.js

 import {expect} from 'chai'
 var sinon = require('sinon')
+import axios from 'axios'
 import moxios from 'moxios'
 import store from '@/store/instance'
 import { testAction } from '../../utils'
@@ -14,6 +15,7 @@ describe('store/instance', () => {
   afterEach(function () {
     sandbox.restore()
     moxios.uninstall()
+    axios.defaults.baseURL = null
   })
 
   describe('mutations', () => {