chore(package): update concurrently to version 5.0.1

Closes #586

Author: greenkeeper[bot]

package.json

@@ -139,7 +139,7 @@
     "bootstrap-sass": "^3.3.7",
     "chai": "^4.1.1",
     "clean-webpack-plugin": "^2.0.1",
-    "concurrently": "^4.0.1",
+    "concurrently": "^5.0.1",
     "cross-env": "^5.1.1",
     "css-loader": "^1.0.0",
     "eslint": "^5.2.0",