Add missing eslint-plugin-filenames dev dependency

Author: Tom Kirkpatrick

package.json

@@ -43,6 +43,7 @@
     "coveralls": "^2.11.9",
     "eslint": "^3.0.1",
     "eslint-config-fullcube": "git+https://github.com/fullcube/eslint-config-fullcube.git",
+    "eslint-plugin-filenames": "^1.0.0",
     "helmet": "^1.3.0",
     "loglevel": "^1.4.1",
     "loopback": "^2.22.0",