Update to vue-cli 3 when it is released and stable

[ais-one]

vue-cli 3 still supports templates, but we would like to take advantage of the plugin way of doing things in vue-cli 3 and will move to it once it is stable

https://github.com/vuejs/vue-cli/blob/dev/docs/cli.md#pulling-vue-cli2x-templates-legacy

[ais-one]

now using vue-cli 3