Migrate to vue-cli 3

[gick]

The repo is based on an outdated version of vue-cli. Migrating to vue-cli-3 would allow to use Webpack 4 which greatly reduces the first load time and the compilation time.
As a bonus, vue-cli-3 takes care of Webpack and Babel management by default, which means less config files.
Would be happy to make a PR since I migrated a project based on this repo to vue-cli-3 recently.

[thinkive]

需要作者更新到vue-cli-3

[MattiaFailla]

Hey @gick do you have any instructions on how to update to vue-cli-3?