chore(package): update eslint to version 6.4.0

Closes #71

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
 		"chai": "^4.2.0",
 		"chai-as-promised": "7.1.1",
 		"coveralls": "^3.0.2",
-		"eslint": "^5.8.0",
+		"eslint": "^6.4.0",
 		"eslint-config-cortys": "1.x",
 		"gulp": "3.9.1",
 		"gulp-eslint": "^5.0.0",