Bump electron from 2.0.18 to 6.0.3

Bumps [electron](https://github.com/electron/electron) from 2.0.18 to 6.0.3.
- [Release notes](https://github.com/electron/electron/releases)
- [Commits](https://github.com/electron/electron/compare/v2.0.18...v6.0.3)

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

package.json

@@ -3,7 +3,7 @@
   "version": "1.0.0",
   "main": "app.js",
   "dependencies": {
-    "electron": "^2.0.18",
+    "electron": "^6.0.3",
     "socket.io": "*"
   },
   "repository": {