chore(package): update @babel/preset-env to version 7.5.4

Closes #175

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
   },
   "devDependencies": {
     "@babel/core": "7.5.4",
-    "@babel/preset-env": "7.5.0",
+    "@babel/preset-env": "7.5.4",
     "del": "5.0.0",
     "eslint": "6.0.1",
     "eslint-config-google": "0.13.0",