chore(package): update cross-env to version 7.0.1

Closes #67

Author: greenkeeper[bot]

package.json

@@ -65,7 +65,7 @@
     "babel-tape-runner": "^2.0.1",
     "babelify": "^7.3.0",
     "browserify": "^14.0.0",
-    "cross-env": "^5.1.1",
+    "cross-env": "^7.0.1",
     "devtool": "^2.2.0",
     "dmn": "^1.0.5",
     "doctoc": "^1.2.0",