Bump urllib3 from 1.23 to 1.26.5

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.23 to 1.26.5.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.23...1.26.5)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -20,6 +20,6 @@ PyYAML==3.12
 requests==2.19.1
 tablib==0.12.1
 unicodecsv==0.14.1
-urllib3==1.23
+urllib3==1.26.5
 xlrd==1.1.0
 xlwt==1.3.0