Create a test vue page and set up Laravel Mix

[murrant]

How to use:

1. Add a hosts entry for librenmsv2.local (temporary step for now)
2. Install and start redis
3. composer install
4. npm install
5. npm run dev
6. npm run dev-echo-server

Browse to http://librenmsv2.local/vue

[mention-bot]

@murrant, thanks for your PR! By analyzing the history of the files in this pull request, we identified @laf to be a potential reviewer.