Bump vue-server-renderer from 2.6.6 to 2.6.7

Bumps [vue-server-renderer](https://github.com/vuejs/vue) from 2.6.6 to 2.6.7.
- [Release notes](https://github.com/vuejs/vue/releases)
- [Commits](vuejs/vue@v2.6.6...v2.6.7)

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

package.json

@@ -39,7 +39,7 @@
     "socket.io": "^2.2.0",
     "socket.io-client": "^2.2.0",
     "vue": "^2.5.22",
-    "vue-server-renderer": "2.6.6",
+    "vue-server-renderer": "2.6.7",
     "vueify": "^9.4.1",
     "watchify": "^3.11.1"
   },