chore(deps): bump whatwg-fetch from 3.6.2 to 3.6.18

Bumps [whatwg-fetch](https://github.com/github/fetch) from 3.6.2 to 3.6.18.
- [Release notes](https://github.com/github/fetch/releases)
- [Changelog](https://github.com/JakeChampion/fetch/blob/master/CHANGELOG.md)
- [Commits](JakeChampion/fetch@v3.6.2...v3.6.18)

---
updated-dependencies:
- dependency-name: whatwg-fetch
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -63,7 +63,7 @@
         "redux-thunk": "^2.4.2",
         "reselect": "^4.1.7",
         "styled-jsx": "^4",
-        "whatwg-fetch": "^3.6.2"
+        "whatwg-fetch": "^3.6.18"
     },
     "jest": {
         "transformIgnorePatterns": [

yarn.lock

@@ -15820,10 +15820,10 @@ whatwg-encoding@^1.0.1, whatwg-encoding@^1.0.3, whatwg-encoding@^1.0.5:
   dependencies:
     iconv-lite "0.4.24"
 
-whatwg-fetch@>=0.10.0, whatwg-fetch@^3.6.2:
-  version "3.6.2"
-  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-3.6.2.tgz#dced24f37f2624ed0281725d51d0e2e3fe677f8c"
-  integrity sha512-bJlen0FcuU/0EMLrdbJ7zOnW6ITZLrZMIarMUVmdKtsGvZna8vxKYaexICWPfZ8qwf9fzNq+UEIZrnSaApt6RA==
+whatwg-fetch@>=0.10.0, whatwg-fetch@^3.6.18, whatwg-fetch@^3.6.2:
+  version "3.6.18"
+  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-3.6.18.tgz#2f640cdee315abced7daeaed2309abd1e44e62d4"
+  integrity sha512-ltN7j66EneWn5TFDO4L9inYC1D+Czsxlrw2SalgjMmEMkLfA5SIZxEFdE6QtHFiiM6Q7WL32c7AkI3w6yxM84Q==
 
 whatwg-mimetype@^2.1.0, whatwg-mimetype@^2.2.0, whatwg-mimetype@^2.3.0:
   version "2.3.0"