chore(package): update cross-env to version 6.0.0

Author: greenkeeper[bot]

package.json

@@ -56,7 +56,7 @@
     "chai-as-promised": "7.1.1",
     "codecov": "^3.5.0",
     "commitlint-config-travi": "^1.3.3",
-    "cross-env": "^5.2.0",
+    "cross-env": "^6.0.0",
     "cucumber": "^5.1.0",
     "cz-conventional-changelog": "^3.0.2",
     "globstar": "1.0.0",