chore(package): update eslint-plugin-promise to version 4.2.1

Closes #5

Author: greenkeeper[bot]

package.json

@@ -19,7 +19,7 @@
     "eslint-config-standard": "^11.0.0",
     "eslint-plugin-import": "^2.8.0",
     "eslint-plugin-node": "^6.0.0",
-    "eslint-plugin-promise": "^3.6.0",
+    "eslint-plugin-promise": "^4.2.1",
     "eslint-plugin-standard": "^3.0.1",
     "globby": "^8.0.1",
     "jest": "^22.3.0"