chore(package): update loopback to version 3.19.0

Closes #28

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "eslint": "4.1.1",
     "eslint-config-fullcube": "3.0.0",
     "husky": "0.14.1",
-    "loopback": "3.8.0",
+    "loopback": "3.19.0",
     "loopback-connector-mongodb": "3.2.0",
     "loopback-testing": "1.4.0",
     "mocha": "3.4.2",