chore(package): update lockfile yarn.lock

Author: greenkeeper[bot]

yarn.lock

@@ -7241,10 +7241,10 @@ webpack-sources@^1.1.0, webpack-sources@^1.3.0:
     source-list-map "^2.0.0"
     source-map "~0.6.1"
 
-webpack@^4.26.0:
-  version "4.26.0"
-  resolved "https://registry.yarnpkg.com/webpack/-/webpack-4.26.0.tgz#adbe80b869148c8d108b7d88965d00d72b3178de"
-  integrity sha512-J/dP9SJIc5OtX2FZ/+U9ikQtd6H6Mcbqt0xeXtmPwYGDKf8nkbOQQA9KL2Y0rJOsN1Al9Pdn+/j63X58ub8gvQ==
+webpack@^4.28.4:
+  version "4.28.4"
+  resolved "https://registry.yarnpkg.com/webpack/-/webpack-4.28.4.tgz#1ddae6c89887d7efb752adf0c3cd32b9b07eacd0"
+  integrity sha512-NxjD61WsK/a3JIdwWjtIpimmvE6UrRi3yG54/74Hk9rwNj5FPkA4DJCf1z4ByDWLkvZhTZE+P3C/eh6UD5lDcw==
   dependencies:
     "@webassemblyjs/ast" "1.7.11"
     "@webassemblyjs/helper-module-context" "1.7.11"