Bump vue from 2.5.17 to 2.6.11

Bumps [vue](https://github.com/vuejs/vue) from 2.5.17 to 2.6.11.
- [Release notes](https://github.com/vuejs/vue/releases)
- [Commits](vuejs/vue@v2.5.17...v2.6.11)

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

package.json

@@ -39,7 +39,7 @@
     "relative-date": "^1.1.3",
     "socket.io": "^2.3.0",
     "socket.io-client": "^2.3.0",
-    "vue": "2.5.17",
+    "vue": "2.6.11",
     "vue-router": "^3.1.6",
     "vue-server-renderer": "2.5.17",
     "vueify": "^9.4.1",