Update dependency tslint to v5.15.0 (#155)

Author: renovate-bot

package.json

@@ -46,7 +46,7 @@
     "rimraf": "2.6.3",
     "rollup": "0.67.4",
     "rollup-plugin-copy": "1.1.0",
-    "tslint": "5.13.0",
+    "tslint": "5.15.0",
     "typescript": "3.4.3"
   },
   "files": [