[Security] Bump electron from 1.8.8 to 2.0.18

Bumps [electron](https://github.com/electron/electron) from 1.8.8 to 2.0.18. **This update includes a security fix.**
- [Release notes](https://github.com/electron/electron/releases)
- [Commits](https://github.com/electron/electron/compare/v1.8.8...v2.0.18)

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

package.json

@@ -87,7 +87,7 @@
     "css-loader": "^0.28.4",
     "del": "^3.0.0",
     "devtron": "^1.4.0",
-    "electron": "^1.7.5",
+    "electron": "^2.0.18",
     "electron-builder": "^19.19.1",
     "electron-debug": "^1.4.0",
     "electron-devtools-installer": "^2.2.0",