chore(deps): update dependency @babel/core to v7.6.4

Author: renovate-bot

package-lock.json

@@ -30,7 +30,7 @@
     "@apollo/react-testing": "file:./packages/testing"
   },
   "devDependencies": {
-    "@babel/core": "7.6.2",
+    "@babel/core": "7.6.4",
     "@babel/plugin-transform-modules-commonjs": "7.6.0",
     "@babel/plugin-transform-modules-umd": "7.2.0",
     "@testing-library/react": "9.3.0",