Bump vuex from 2.5.0 to 3.1.1

Bumps [vuex](https://github.com/vuejs/vuex) from 2.5.0 to 3.1.1.
- [Release notes](https://github.com/vuejs/vuex/releases)
- [Commits](https://github.com/vuejs/vuex/compare/v2.5.0...v3.1.1)

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

package.json

@@ -66,7 +66,7 @@
     "vue-electron": "^1.0.6",
     "vue-router": "^2.5.3",
     "vuetify": "1.0.0",
-    "vuex": "^2.3.1"
+    "vuex": "^3.1.1"
   },
   "devDependencies": {
     "@fortawesome/fontawesome-free": "^5.3.1",