Bump @babel/plugin-proposal-class-properties from 7.7.0 to 7.7.4

Bumps [@babel/plugin-proposal-class-properties](https://github.com/babel/babel) from 7.7.0 to 7.7.4.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.7.0...v7.7.4)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -42,7 +42,7 @@
   "license": "MIT",
   "devDependencies": {
     "@babel/core": "7.7.2",
-    "@babel/plugin-proposal-class-properties": "^7.7.0",
+    "@babel/plugin-proposal-class-properties": "^7.7.4",
     "@babel/preset-env": "^7.7.4",
     "@babel/preset-react": "^7.7.0",
     "@svgr/webpack": "4.3.3",