chore(package): update chalk to version 4.0.0

Closes #133

Author: greenkeeper[bot]

package.json

@@ -43,7 +43,7 @@
     "ava": "^1.1.0",
     "babel-eslint": "^10.0.1",
     "babel-plugin-istanbul": "^5.1.0",
-    "chalk": "^2.4.2",
+    "chalk": "^4.0.0",
     "classnames": "^2.2.6",
     "codecov": "^3.1.0",
     "coveralls": "^3.0.2",