chore(deps): bump streamx from 2.18.0 to 2.20.0

Bumps [streamx](https://github.com/mafintosh/streamx) from 2.18.0 to 2.20.0.
- [Commits](mafintosh/streamx@v2.18.0...v2.20.0)

---
updated-dependencies:
- dependency-name: streamx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -50,7 +50,7 @@
     "gulp": "^5.0.0",
     "lodash.assign": "^4.2.0",
     "plugin-error": "^2.0.1",
-    "streamx": "^2.18.0"
+    "streamx": "^2.20.0"
   },
   "version": "0.0.0-development",
   "publishConfig": {