chore(deps): update dependency semantic-release to v15.13.18

Author: renovate-bot

package.json

@@ -71,7 +71,7 @@
     "jshint-summary": "0.4.0",
     "matchdep": "1.0.1",
     "mocha": "5.2.0",
-    "semantic-release": "15.13.17",
+    "semantic-release": "15.13.18",
     "travis-deploy-once": "4.4.1"
   },
   "engines": {