Bump vue from 2.6.7 to 2.6.8

Bumps [vue](https://github.com/vuejs/vue) from 2.6.7 to 2.6.8.
- [Release notes](https://github.com/vuejs/vue/releases)
- [Commits](vuejs/vue@v2.6.7...v2.6.8)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -38,7 +38,7 @@
     "relative-date": "^1.1.3",
     "socket.io": "^2.2.0",
     "socket.io-client": "^2.2.0",
-    "vue": "^2.6.7",
+    "vue": "^2.6.8",
     "vue-server-renderer": "2.6.8",
     "vueify": "^9.4.1",
     "watchify": "^3.11.1"