Update gatsby to version 2.17.11 (#14)

Author: depfu[bot]

package.json

@@ -39,7 +39,7 @@
     "eslint-plugin-promise": "^4.2.1",
     "eslint-plugin-react": "^7.16.0",
     "eslint-plugin-standard": "^4.0.1",
-    "gatsby": "^2.17.10",
+    "gatsby": "^2.17.11",
     "react": "^16.11.0",
     "react-dom": "^16.11.0",
     "react-helmet-async": "^1.0.4",