fix: upgrade multiple dependencies with Snyk

Snyk has created this PR to upgrade:
  - gatsby from 2.21.11 to 2.21.13.
    See this package in NPM: https://www.npmjs.com/package/gatsby
  - gatsby-plugin-manifest from 2.4.1 to 2.4.2.
    See this package in NPM: https://www.npmjs.com/package/gatsby-plugin-manifest

See this project in Snyk:
https://app.snyk.io/org/creyd-github-marketplace/project/7687a902-5880-4dba-8e64-1ed2c0311711?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -16,8 +16,8 @@
   },
   "dependencies": {
     "dateformat": "^3.0.3",
-    "gatsby": "^2.21.11",
-    "gatsby-plugin-manifest": "^2.4.1",
+    "gatsby": "^2.21.13",
+    "gatsby-plugin-manifest": "^2.4.2",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
     "snyk": "^1.317.0"