chore(package): update loopback to version 3.18.3

Closes #35

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "dirty-chai": "2.0.0",
     "eslint-config-fullcube": "3.0.0",
     "husky": "0.14.2",
-    "loopback": "3.8.0",
+    "loopback": "3.18.3",
     "loopback-boot": "2.25.0",
     "loopback-connector-mongodb": "3.2.0",
     "loopback-testing": "1.4.0",