Bump babel-core from 6.26.0 to 6.26.3

Bumps [babel-core](https://github.com/babel/babel) from 6.26.0 to 6.26.3.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/compare/v6.26.0...v6.26.3)

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

package.json

@@ -24,7 +24,7 @@
   "devDependencies": {
     "async": "1.5.2",
     "autoprefixer": "7.1.3",
-    "babel-core": "6.26.0",
+    "babel-core": "6.26.3",
     "babel-eslint": "8.0.1",
     "babel-loader": "7.1.1",
     "babel-plugin-transform-object-rest-spread": "6.26.0",