chore(package): update tslint to version 5.7.0

Closes #30

Author: greenkeeper[bot]

package.json

@@ -47,7 +47,7 @@
     "should": "11.2.1",
     "ts-loader": "2.3.3",
     "tslib": "1.7.1",
-    "tslint": "5.6.0",
+    "tslint": "5.7.0",
     "tslint-loader": "3.5.3",
     "typedoc": "0.8.0",
     "typescript": "2.4.2",