chore(package): update cypress to version 4.0.2

Closes #45

Author: greenkeeper[bot]

package.json

@@ -5,7 +5,7 @@
   "devDependencies": {
     "cross-env": "^5.2.0",
     "css-loader": "3.0.0",
-    "cypress": "^3.2.0",
+    "cypress": "^4.0.2",
     "http-server": "^0.11.1",
     "mini-css-extract-plugin": "^0.7.0",
     "npm-run-all": "^4.1.5",