Bump cachetools from 3.0.0 to 3.1.0

Bumps [cachetools](https://github.com/tkem/cachetools) from 3.0.0 to 3.1.0.
- [Release notes](https://github.com/tkem/cachetools/releases)
- [Changelog](https://github.com/tkem/cachetools/blob/master/CHANGES.rst)
- [Commits](tkem/cachetools@v3.0.0...v3.1.0)

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

Author: dependabot-support

requirements.txt

@@ -2,7 +2,7 @@ asn1crypto==0.24.0
 auth0-python==3.6.1
 boto3==1.9.86
 botocore==1.12.86
-cachetools==3.0.0
+cachetools==3.1.0
 certifi==2018.11.29
 cffi==1.11.5
 chardet==3.0.4