[Bug Report] V-toolbar: Extension slot not working with the new Vue 2.6 slot syntax

[razorfever]

Versions and Environment

Vuetify: 1.5.0
Vue: 2.6.1
Browsers: Chrome 74.0.3693.0
OS: Mac OS 10.14.0

Steps to reproduce

Open the expansion slot demo for the v-toolbar in codepen and convert the syntax to match the new slot syntax in Vue 2.6

Expected Behavior

Title shows up in the expansion slot

Actual Behavior

Title does not show up in the expansion slot

Reproduction Link

https://codepen.io/anon/pen/OdxLxM?&editable=true&editors=101

[DRoet]

Try upgrading to vue 2.6.2, it seems to work: https://codepen.io/anon/pen/yZzqgq?&editable=true&editors=101

[KaelWD]

Duplicate of vuejs/vue#9421