chore(package): update @babel/preset-env to version 7.9.6

Closes #167

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
   },
   "devDependencies": {
     "@babel/core": "7.9.6",
-    "@babel/preset-env": "7.8.7",
+    "@babel/preset-env": "7.9.6",
     "@babel/template": "7.8.6",
     "babel-jest": "24.9.0",
     "commitizen": "3.1.2",