Bump async from 2.5.0 to 2.6.4

Bumps [async](https://github.com/caolan/async) from 2.5.0 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/v2.5.0...v2.6.4)

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

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

package-lock.json

@@ -108,17 +108,17 @@
       "integrity": "sha1-104bh+ev/A24qttwIfP+SBAasjQ="
     },
     "async": {
-      "version": "2.5.0",
-      "resolved": "https://registry.npmjs.org/async/-/async-2.5.0.tgz",
-      "integrity": "sha512-e+lJAJeNWuPCNyxZKOBdaJGyLGHugXVQtrAwtuAe2vhxTYxFTKE73p8JuTmdH0qdQZtDvI4dhJwjZc5zsfIsYw==",
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
       "requires": {
-        "lodash": "^4.14.0"
+        "lodash": "^4.17.14"
       },
       "dependencies": {
         "lodash": {
-          "version": "4.17.4",
-          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.4.tgz",
-          "integrity": "sha1-eCA6TRwyiuHYbcpkYONptX9AVa4="
+          "version": "4.17.21",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+          "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
         }
       }
     },

package.json

@@ -21,7 +21,7 @@
   "homepage": "https://github.com/koodiklinikka/koodiklinikka.fi-api",
   "dependencies": {
     "apicache": "0.0.12",
-    "async": "^2.5.0",
+    "async": "^2.6.4",
     "bluebird": "^2.9.3",
     "body-parser": "^1.10.1",
     "cors": "^2.7.1",