Update install method

Update install method to avoid .use issue. Thank you @queengooborg.

Update demo build

v6.0.3

Update demo build

Update demo build

v6.0.2

Update demo build

Update demo build

v6.0.1

Update demo build

Upgrade to Vue 3

Vue 3 is supported from v6.0.0 and beyond (current master). To use vue-cookie-accept-decline with Vue 2, use v5.4.0.