build(deps): bump flake8-tidy-imports from 1.1.0 to 4.2.1 (#844)

Bumps [flake8-tidy-imports](https://github.com/adamchainz/flake8-tidy-imports) from 1.1.0 to 4.2.1.
- [Release notes](https://github.com/adamchainz/flake8-tidy-imports/releases)
- [Changelog](https://github.com/adamchainz/flake8-tidy-imports/blob/master/HISTORY.rst)
- [Commits](https://github.com/adamchainz/flake8-tidy-imports/compare/1.1.0...4.2.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

requirements.txt

@@ -6,7 +6,7 @@ flake8==3.8.4
 # A flake8 plugin that helps you write tidier imports.
 # License: ISCL
 # Upstream url: https://pypi.python.org/pypi/flake8-tidy-imports
-flake8-tidy-imports==1.1.0
+flake8-tidy-imports==4.2.1
 
 # A mature full-featured Python testing tool.
 # License: MIT