Bump @material-ui/core from 4.9.11 to 4.9.12

Bumps [@material-ui/core](https://github.com/mui-org/material-ui/tree/HEAD/packages/material-ui) from 4.9.11 to 4.9.12.
- [Release notes](https://github.com/mui-org/material-ui/releases)
- [Changelog](https://github.com/mui-org/material-ui/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mui-org/material-ui/commits/v4.9.12/packages/material-ui)

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

package.json

@@ -15,7 +15,7 @@
   "license": "BSD-3-Clause",
   "version": "0.7.1",
   "dependencies": {
-    "@material-ui/core": "4.9.11",
+    "@material-ui/core": "4.9.12",
     "@material-ui/icons": "^4.9.1",
     "@muetab/quotes": "^1.0.0",
     "react": "^16.13.1",