Update dependency whatwg-fetch to v3.6.1

Author: renovate-bot

package.json

@@ -47,7 +47,7 @@
  "react-helmet": "5.2.1",
  "react-stripe-elements": "6.1.2",
  "styled-components": "4.4.1",
- "whatwg-fetch": "3.0.0"
+ "whatwg-fetch": "3.6.1"
  },
  "devDependencies": {
  "@babel/core": "7.7.7",

yarn.lock

@@ -14559,7 +14559,12 @@ whatwg-fetch@2.0.4:
  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-2.0.4.tgz#dde6a5df315f9d39991aa17621853d720b85566f"
  integrity sha512-dcQ1GWpOD/eEQ97k66aiEVpNnapVj90/+R+SXTPYGHpYBBypfKJEQjLrvMZ7YXbKm21gXd4NcuxUTjiv1YtLng==
 
-whatwg-fetch@3.0.0, whatwg-fetch@>=0.10.0:
+whatwg-fetch@3.6.1:
+ version "3.6.1"
+ resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-3.6.1.tgz#93bc4005af6c2cc30ba3e42ec3125947c8f54ed3"
+ integrity sha512-IEmN/ZfmMw6G1hgZpVd0LuZXOQDisrMOZrzYd5x3RAK4bMPlJohKUZWZ9t/QsTvH0dV9TbPDcc2OSuIDcihnHA==
+
+whatwg-fetch@>=0.10.0:
  version "3.0.0"
  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-3.0.0.tgz#fc804e458cc460009b1a2b966bc8817d2578aefb"
  integrity sha512-9GSJUgz1D4MfyKU7KRqwOjXCXTqWdFNvEr7eUBYchQiVc744mqK/MzXPNR2WsPkmkOa4ywfg8C2n8h+13Bey1Q==