Update dependency @babel/core to v7.6.4 (#37)

Author: renovate[bot]

package-lock.json

@@ -34,7 +34,7 @@
     "react-dom": "^16.10.2"
   },
   "devDependencies": {
-    "@babel/core": "7.6.0",
+    "@babel/core": "7.6.4",
     "@svgr/webpack": "4.3.3",
     "@typescript-eslint/eslint-plugin": "2.4.0",
     "@typescript-eslint/parser": "2.4.0",