Bump future from 0.18.2 to 0.18.3

Bumps [future](https://github.com/PythonCharmers/python-future) from 0.18.2 to 0.18.3.
- [Release notes](https://github.com/PythonCharmers/python-future/releases)
- [Changelog](https://github.com/PythonCharmers/python-future/blob/master/docs/changelog.rst)
- [Commits](PythonCharmers/python-future@v0.18.2...v0.18.3)

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

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

requirements.txt

@@ -6,7 +6,7 @@ charset-normalizer==2.1.1
 colorama==0.4.5
 discord-webhook==0.16.1
 docopt==0.6.2
-future==0.18.2
+future==0.18.3
 gdtoolkit==3.4.0
 google-api-core==2.7.3
 google-api-python-client==2.47.0