Bump urllib3 from 1.24.1 to 1.24.2

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.24.1 to 1.24.2.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/master/CHANGES.rst)
- [Commits](urllib3/urllib3@1.24.1...1.24.2)

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

Author: dependabot[bot]

requirements.txt

@@ -78,7 +78,7 @@ testpath==0.4.2
 tornado==5.1.1
 traitlets==4.3.2
 tzlocal==1.5.1
-urllib3==1.24.1
+urllib3==1.24.2
 wcwidth==0.1.7
 webencodings==0.5.1
 widgetsnbextension==3.4.2