chore(package): update cross-env to version 7.0.0

Closes #3

Author: greenkeeper[bot]

package.json

@@ -49,7 +49,7 @@
     "babel-plugin-istanbul": "^5.2.0",
     "babel-preset-minify": "^0.5.0",
     "chai": "^4.2.0",
-    "cross-env": "^5.2.0",
+    "cross-env": "^7.0.0",
     "eslint": "^6.1.0",
     "eslint-config-airbnb": "^17.1.1",
     "eslint-plugin-import": "^2.18.2",