chore(deps): bump wkhtmltopdf-binary from 0.12.6.6 to 0.12.6.7

Bumps [wkhtmltopdf-binary](https://github.com/zakird/wkhtmltopdf_binary_gem) from 0.12.6.6 to 0.12.6.7.
- [Release notes](https://github.com/zakird/wkhtmltopdf_binary_gem/releases)
- [Changelog](https://github.com/zakird/wkhtmltopdf_binary_gem/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zakird/wkhtmltopdf_binary_gem/compare/0.12.6.6...0.12.6.7)

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

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

Gemfile.lock

@@ -819,7 +819,7 @@ GEM
       chronic (>= 0.6.3)
     wicked_pdf (2.6.3)
       activesupport
-    wkhtmltopdf-binary (0.12.6.6)
+    wkhtmltopdf-binary (0.12.6.7)
     xml-simple (1.1.8)
     xpath (3.2.0)
       nokogiri (~> 1.8)