Improve build times

* Fix bulma/buefy being imported many (many !!!) times

* Remove javascript-time-ago because date-fns pretty much does the same
thing

* Make sure languages are loaded asynchronously

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/Event/EventCard.vue

@@ -115,8 +115,6 @@ export default class EventCard extends Vue {
 </script>
 
 <style lang="scss" scoped>
-@import "../../variables";
-
 a.card {
   display: block;
   background: $secondary;