chore(package): update cross-env to version 6.0.2

Closes #402

Author: greenkeeper[bot]

package.json

@@ -86,7 +86,7 @@
     "bundlesize": "^0.18.0",
     "chai": "^4.2.0",
     "create-react-class": "^15.6.3",
-    "cross-env": "^5.2.0",
+    "cross-env": "^6.0.2",
     "cypress": "^3.2.0",
     "eslint": "^5.16.0",
     "eslint-import-resolver-webpack": "^0.11.1",