chore(deps): update tox requirement from ~=3.21 to ~=3.22 (appium#586)

Updates the requirements on [tox](https://github.com/tox-dev/tox) to permit the latest version.
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/master/docs/changelog.rst)
- [Commits](tox-dev/tox@3.21.0...3.22.0)

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

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

Author: dependabot[bot]

Pipfile

@@ -14,7 +14,7 @@ black = "==20.8b1"
 pytest = "~=6.2"
 pytest-cov = "~=2.11"
 
-tox = "~=3.21"
+tox = "~=3.22"
 
 httpretty = "~=1.0"
 python-dateutil = "~=2.8"