Bump lxml from 4.6.3 to 4.6.5 in /tests (#515)

Bumps [lxml](https://github.com/lxml/lxml) from 4.6.3 to 4.6.5.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-4.6.3...lxml-4.6.5)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

tests/requirements.txt

@@ -1,7 +1,7 @@
 pytest==5.3.5
 pytest_check==0.3.8
 regex==2020.4.4
-lxml==4.6.3
+lxml==4.6.5
 requests==2.22.0
 pandas==1.3.3
 beautifulsoup4==4.9.0