Fix console.errors in frontend tests

@MoldaB here's how you can register plugins in a frontend test. Pro tip:
You can run `yarn run test --run-in-band` to find out where the
console.errors come from. Jest, by default, runs in parallel which makes
it a little difficult to debug errors that don't fail the test.

webapp/pages/index.spec.js

@@ -5,6 +5,7 @@ import Styleguide from '@human-connection/styleguide'
 import Filters from '~/plugins/vue-filters'
 import VTooltip from 'v-tooltip'
 import FilterMenu from '~/components/FilterMenu/FilterMenu'
+import InfiniteScroll from '~/plugins/vue-infinite-scroll'
 
 const localVue = createLocalVue()
 
@@ -12,6 +13,7 @@ localVue.use(Vuex)
 localVue.use(Styleguide)
 localVue.use(Filters)
 localVue.use(VTooltip)
+localVue.use(InfiniteScroll)
 
 config.stubs['no-ssr'] = '<span><slot /></span>'
 config.stubs['router-link'] = '<span><slot /></span>'

webapp/pages/profile/_id/_slug.spec.js

@@ -3,12 +3,14 @@ import ProfileSlug from './_slug.vue'
 import Vuex from 'vuex'
 import Styleguide from '@human-connection/styleguide'
 import Filters from '~/plugins/vue-filters'
+import InfiniteScroll from '~/plugins/vue-infinite-scroll'
 
 const localVue = createLocalVue()
 
 localVue.use(Vuex)
 localVue.use(Styleguide)
 localVue.use(Filters)
+localVue.use(InfiniteScroll)
 localVue.filter('date', d => d)
 
 config.stubs['no-ssr'] = '<span><slot /></span>'

webapp/plugins/vue-infinite-scroll.js

@@ -1,4 +1,4 @@
-import Vue from 'vue'
-import infiniteScroll from 'vue-infinite-scroll'
-
-Vue.use(infiniteScroll)
+import Vue from 'vue'
+import infiniteScroll from 'vue-infinite-scroll'
+
+Vue.use(infiniteScroll)