Bump bl from 5.1.0 to 6.0.1

Bumps [bl](https://github.com/rvagg/bl) from 5.1.0 to 6.0.1.
- [Release notes](https://github.com/rvagg/bl/releases)
- [Changelog](https://github.com/rvagg/bl/blob/master/CHANGELOG.md)
- [Commits](rvagg/bl@v5.1.0...v6.0.1)

---
updated-dependencies:
- dependency-name: bl
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package.json

@@ -11,7 +11,7 @@
     "xtend": "^4.0.1"
   },
   "devDependencies": {
-    "bl": "^5.0.0",
+    "bl": "^6.1.6",
     "browserify": "^17.0.0",
     "from2-string": "^1.1.0",
     "standard": "^17.0.0",