Bump async from 2.6.1 to 2.6.4

Bumps [async](https://github.com/caolan/async) from 2.6.1 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v2.6.1...v2.6.4)

---
updated-dependencies:
- dependency-name: async
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

yarn.lock

@@ -69,11 +69,11 @@ argparse@^1.0.7:
     sprintf-js "~1.0.2"
 
 async@^2.6.1:
-  version "2.6.1"
-  resolved "https://registry.yarnpkg.com/async/-/async-2.6.1.tgz#b245a23ca71930044ec53fa46aa00a3e87c6a610"
-  integrity sha512-fNEiL2+AZt6AlAw/29Cr0UDe4sRAHCpEHh54WMz+Bb7QfNcFw4h3loofyJpLeQs4Yx7yuqu/2dLgM5hKOs6HlQ==
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.4.tgz#706b7ff6084664cd7eae713f6f965433b5504221"
+  integrity sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==
   dependencies:
-    lodash "^4.17.10"
+    lodash "^4.17.14"
 
 axios@^0.18.0:
   version "0.18.0"
@@ -562,10 +562,10 @@ levn@^0.3.0, levn@~0.3.0:
     prelude-ls "~1.1.2"
     type-check "~0.3.2"
 
-lodash@^4.17.10, lodash@^4.17.4, lodash@^4.3.0:
-  version "4.17.11"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
-  integrity sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==
+lodash@^4.17.14, lodash@^4.17.4, lodash@^4.3.0:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 lru-cache@^4.0.1:
   version "4.1.5"