Bump vow from 0.4.19 to 0.4.20

Bumps [vow](https://github.com/dfilatov/vow) from 0.4.19 to 0.4.20.
- [Release notes](https://github.com/dfilatov/vow/releases)
- [Changelog](https://github.com/dfilatov/vow/blob/master/CHANGELOG.md)
- [Commits](https://github.com/dfilatov/vow/commits)

---
updated-dependencies:
- dependency-name: vow
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -21,7 +21,7 @@
     "gonzales-pe": "4.2.4",
     "minimatch": "3.0.4",
     "minimist": "1.2.0",
-    "vow": "0.4.19",
+    "vow": "0.4.20",
     "vow-fs": "0.3.6"
   },
   "devDependencies": {