Update element-ui requirement from 2.11.1 to 2.12.0 (#23)

Updates the requirements on [element-ui](https://github.com/ElemeFE/element) to permit the latest version.
- [Release notes](https://github.com/ElemeFE/element/releases)
- [Changelog](https://github.com/ElemeFE/element/blob/dev/CHANGELOG.en-US.md)
- [Commits](ElemeFE/element@v2.11.1...v2.12.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -21,7 +21,7 @@
   "dependencies": {
     "electron-context-menu": "0.15.0",
     "electron-updater": "4.1.2",
-    "element-ui": "2.11.1",
+    "element-ui": "2.12.0",
     "core-js": "2.6.5",
     "vue": "2.6.10",
     "vue-router": "3.1.2"